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learning about online stores **[|eCommerce Mastery]**Chapter 1 and Chapter 3 Editor: Erin Garrity Period G

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Vocabulary: Roll over for definition or see the caption below each. == Group 1 == Co-editor: Lauren Altmeyer

Group Members: Abby John, Grayce Rose, and Lauren Altmeyer == (What is Chemistry? Pgs. 7-11) ==

=== Intro to Chemistry === === (Abby John pgs. 7-8) === === Chemistry is the study of matter and the changes it undergoes. ===
 * matter is anything with mass
 * because living and non living things are made up of matter chemistry affects many parts of life

There are five traditional types of chemistry


 * organic chemistry-the study of chemicals containing carbon
 * inorganic chemistry-the study of chemicals not containing carbon
 * biochemistry- the study of the chemical processes in the body
 * analytical chemistry- the study of the composition of matter


 * physical chemistry-the study that deals with mechanism, rate and energy transfer that occurs when matter changes

= = Pure and Applied Chemistry

= = (Lauren Altmeyer pg. 9)

VOCAB

Pure Chemistry- Pursuit of chemical knowledge for your own sake

Applied Chemistry- Research directed towards a goal

Technology- The means by which society provides it members with those things needed and desire


 * Pure research can lead to a goal, but a goal can exist before research is done to explain how it works (nylon and aspirin are examples of this)

NYLON

Can be used for:
 * 1) Fabric
 * 2) Jackets
 * 3) Fishing lines
 * 4) Toothbrush bristles
 * 5) Ropes
 * Can be drawn from long, thin, silk-like fibers

ASPIRIN Used to:


 * 1) Relieve pain
 * 2) Prevent heart attacks
 * 3) Block blood clots from forming
 * Blocks a group of chemicals that cause pain
 * Prescribed by some doctors to take a daily does if you are at risk for heart attack

TECHNOLOGY


 * Allows humans to do things more quickly with less effort
 * Allows people to do things that would other wise be impossible, such as going to the moon

=== Why study chemistry? === (Grayce Rose pgs. 10-11)

Studying chemistry can be useful in many ways. It is useful when:
 * explaining the natural world-to satisify our own curiosity
 * preparing for a career-not only including in the field of science:
 * firefighters need to know which types of chemicals to use to fight fires
 * turf managers and groundskeepers need to have a knowledge of ground chemistry
 * photographeruse chemicals to develop pictures
 * being and informed citizen-with knoweldge of chemistry we are likely to make more informed decisions
 * supporting and funding scientific research can help make new advances in technology
 * it is important to be informed about the research befor supporting it

Group 2

Co-Editor:Kim Kogut

Group Members: Kelsey Sullivan, Lauren Bedard, Kim Kogut

Chapter Section (Pgs 12-19)

==Chemistry Far and Wide == ===Materials and Energy pgs 12 & 13 (Kelsey Sullivan) ===

====Materials: ====
 * Chemists design materials to fit specific needs
 * In 1948 George de Mastrel was hiking and picked up on of the burrs that was stuck to his clothing. He found that every burr was covered with tiny loops that could latch themselves to the loops in woven clothing.
 * In 1955 George designed a tape that resembled the burrs. It was called hook-and-loop tape.
 * Scientists look at the world in two ways:
 * Macroscopic:
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">The world of objects large enough for you to see with without magnification.
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Microscopic:
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">The world of objects that can only be seen under magnification.

====<span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Energy: ====
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Energy is necessary to meet the needs of modern society.
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">The demand for energy continues to increase witht industrialization growing.
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">There are two ways to meet the demand for energy:
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Conservation:
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">The easiest way to conserve energy is through insulation
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Insulation acts as a barrier to heat flow from the inide of a house or the outside of a freezer.
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Chemists have created SEAgel
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">SEAgel is a foam made from seaweed that is so light it can float on bubbles.
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Production:
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Burning coal, petroleum, and natural gas is a great source of energy.
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">They are called fossil fuels because they are formed from remains of ancient plants and animals.
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Fossil fuels are a limited supply.
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Scientists are trying to obtain fuels from plants
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Oil from soy beans is used to make biodiesel.
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Storage:
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Batteries are a good example of energy storage:
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">They use chemicals to store energy that is released as electric current when the batteries are used.
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Batteries can be recharged. Rechargeable batteries are used in cordless tools
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">NASA uses cordless tools to drill on the moon.
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Rechargeable batteries are also used for things like camera's, wireless phones, and laptop computers.

===<span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">The Environment and the Universe === ===<span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">pgs. 16-17 (Lauren Bedard) ===

= = <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">The Environment:

= =


 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">New technologies cause pollutants
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Pollutants: Material found in air, water, or soil that is harmful to humans or other organisms
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Chemists help identify pollutants and prevent pollution
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Identify Pollutants:
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Lead can cause issues in the brain and other serious problems especially in children
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Low levels of lead in blood can cause permanent damage
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Prevent Polution:
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Use of lead was banned in the late 1900’s
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">There is still lead in millions of houses built before 1978
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Prevent lead poisioning by:
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Testing children’s blood for lead
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Regulating sales of homes to families with young children
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Raising public awareness on the issue

<span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">The Universe:


 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">To study the universe, chemists gather data from afar and analyze matter that is brought back to Earth
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">1800’s- scientists begin to study the composition of stars
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Helium:
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Peirre Janssen: discovered it on sun’s surface
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Norman Lockyer: named it
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">William Ramsay: discovered it on Earth
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Scientists depend on matter brought back to earth by astronauts to study moon/planets

<span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Medicine, Biotechnology, and Agriculture

<span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">pg 14-15 Kim Kogut

<span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Chemistry supplies medicines, materials, and technology that doctors use.

<span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">Chemists help find safer and more productive ways to grow crops.
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">medicines such as perscription drugs are enginereed from chemistry
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">materials suh as used for repairs in the body are created through chemistry
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">biotehnology applies science to the production of biological products


 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">chemists help increase productivity and decrease poor soil quality, weeds, lack of water, diseases and pet problems
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">they genetically modify some plants so that they will thrive
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">farmers used to create chemicals to protect plants from preditors
 * <span style="color: #ff9005; font-family: 'Comic Sans MS',cursive;">chemists help create safer versions of pest prevention

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Group 3

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Co-Editor: Brendan Lynch

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Group Members: Lindsey Bedrosian, Brendan Lynch and Emily Taylor

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Chapter Section (Pgs 20-27)

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">=
<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Thinking Like A Scientist, Pages 20-21 (Lindsey Bedrosian)

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">I. Thinking Like A Scientist

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">A. Alexander Fleming

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">1. Scottish Scientist

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">2. 1928-noticed bacteria didn’t grown on mold

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">a. Assumed that mold released a chemical that prevents the growth of bacteria

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">b. Chemical=penicillin

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">c. 1945- Shared a noble prize with Howard Florey and Ernst Chain who helped isolate penicillin

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">B. Alchemy

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">1. The word chemistry comes from the word alchemy

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">a. Alchemy is the study of matter

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">b. Practiced in China and India as early as 400 B.C.

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">2. Alchemy has 2 sides a. Practical

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">1. Focused on developing techniques by working with metals glass and dyes

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">b. Mystical

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">1. Focuses on concepts like perfection

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">a. Ex. Gold is considered a perfect metal-tried to transform lead into gold

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">C. All Chemists…

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">1. Developed the Tools and Techniques for working with chemicals

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">2. Developed processes for separating mixtures and purifying chemicals

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">3. Designed beakers, flasks, tongs, funnels, mortar and pestle II. An Experimental Approach to Science

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">A. 1500’s-shift from Alchemy to Science

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">B. Science spread in Britain due to King Charles II

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">1. Allowed Royal Society of London for the Promotion of Natural Knowledge to form

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">2. Scientists met and discussed scientific ideas and conducted experiments

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">3. Their aim was to encourage scientists to base their conclusions about the natural world on experimental evidence rather than widely accepted ideas

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">C. Antoine-Laurent Lavoisier

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">1. Helped transform chemistry from science of observation to science of measurement

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">2. Created a balance that could measure mass to the nearest .0005 gram

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">3. Settled the longstanding debate on how materials burn a. Previously, people thought that things burn because they contain phlogiston

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">b. He proved things needed oxygen to burn

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">4. 1794- Arrested, and killed due to his involvement in the taxation D. Marie Ann Lavoisier

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">1. Helped with her husband’s experiments

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">a. Drew pictures of his work and translated his papers from English

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">=
<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Scientific Method, pages 22-23 (Brendan Lynch)

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">The scientific method refers to a body of techniques that are used to answer questions.


 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">created by Roger Bacon
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">used by all scientists
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">used to develop and test theories
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">used to make scientific laws

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Steps

> <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">|| Steps of the Scientific Method || Detailed Help for Each Step ||
 * 1) <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Define the question
 * 2) <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Gather information and resources (observe)
 * 3) <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Form hypothesis
 * 4) <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Perform experiment and collect data
 * 5) <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Analyze data
 * 6) <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Interpret data and draw conclusions that serve as a starting point for new hypothesis
 * 7) <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Publish results
 * 8) <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Retest (frequently done by other scientists)


 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">|| Ask a Question: The scientific method starts when you ask a question about something that you observe: How, What, When, Who, Which, Why, or Where?
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">And, in order for the scientific method to answer the question it must be about something that you can measure, preferably with a number.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">|| Do Background Research: Rather than starting from scratch in putting together a plan for answering your question, you want to be a savvy scientist using library and Internet research to help you find the best way to do things and insure that you don't repeat mistakes from the past.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">|| Construct a Hypothesis: A hypothesis is an educated guess about how things work:
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">"If _[I do this] _, then _[this]_ will happen."You must state your hypothesis in a way that you can easily measure, and of course, your hypothesis should be constructed in a way to help you answer your original question.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">|| Test Your Hypothesis by Doing an Experiment: Your experiment tests whether your hypothesis is true or false. It is important for your experiment to be a fair test. You conduct a fair test by making sure that you change only one factor at a time while keeping all other conditions the same.You should also repeat your experiments several times to make sure that the first results weren't just an accident.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">|| Analyze Your Data and Draw a Conclusion: Once your experiment is complete, you collect your measurements and analyze them to see if your hypothesis is true or false.Scientists often find that their hypothesis was false, and in such cases they will construct a new hypothesis starting the entire process of the scientific method over again. Even if they find that their hypothesis was true, they may want to test it again in a new way.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">|| Communicate Your Results: To complete your science fair project you will communicate your results to others in a final report and/or a display board. Professional scientists do almost exactly the same thing by publishing their final report in a scientific journal or by presenting their results on a poster at a scientific meeting.

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Collaboration and Communication, Pgs. 24-25 (Emily Taylor)

<span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">- When scientists collaborate and communicate, they increase the likelihood of a successful outcome.


 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Collaboration
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Each scientist brings different knowledge or a different approach to solve a problem.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Collaborating is helpful when you need different insights on a particular problem.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Collaboration isn't always easy.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Conflicts about the use of resources, the amount of work, who should receive the credit and when and what information should be published is a lot of material these scientists need to work out.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Communication
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">In earlier centuries, scientists would exchange information through letters, or they would form societies to discuss their latest work.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">These societies began to publish journals of the scientists' work.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Now, many scientists work together so they can communicate with each other face to face.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Many new ideas are exchanged through e-mail, by phone, or at international conferences.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">The most reliable source of information about new discoveries are the scientific journals which are still published.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Readers and reviewers can challenge the scientist's conclusion or ask about the design of the experiment.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Now, the internet is a major source of information.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Everyone can get access to information on the Web.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">Anyone can also post information to the web without getting it reviewed first.
 * <span style="color: #98ff00; font-family: 'Comic Sans MS',cursive;">You should always check the source of the information to make sure it is accurate.

Group 4

Co-editor: Hannah Valley Group Members: Seamus Cuddy, Anne O'Toole, and Hannah Valley Chapter 1 Section 4 (Pgs. 28-32) Problem Solving in Chemistry

Skills Used in Problem Solving (Hannah Valley) ~In the grocery store, there are two brands of one item. How do you decide which brand to purchase? ~You are driving to work and you are already late. Which route would you take, the one that has traffic but is a shorter distance, or the one that is clear of any backup but may be farther? ~You are planning a party. Which appetizer do you think the majority of the guests would like better?
 * Most people do not realize that you use problem solving techniques many times a day
 * Examples:
 * [] shows ways we can solve psycological problems
 * [] gives us tips and insructions how to run a business and deal with any financial or growth problems that may occur within it
 * There are many ways we can figure out a problem including using diagrams, flow charts, and cause and effect, to name a few



Solving Numeric Problems (Anne O'Toole) > *You might want to draw a diagram, table, or graph.*
 * Backround Infomation
 * Measurement is a very important part of chemistry.
 * Most word problems in chemistry require math.
 * For a numeric word problem, the steps for solving are; analyze, calculate, and evaluate.
 * Analyze
 * First, determine where you are starting from (what you know) and where you are going to go (what you don't know).
 * You must plan out the problem to be successful.
 * Now, select a equation that you can use to find the unknown. You can check in the Math Handbook that starts on page R56 for help with equations and math.
 * Calculate
 * This is usually the easiest part of solving a numeric problem.
 * You may need to convert a measurement from one unit to another unit.
 * You also may need to rewrite an equation before you can solve for the unknown.
 * Evaluate
 * After you find an answer evaluate it. This means making sure the answer makes sense, and checking to see if the answer is reasonable. If not, reread the word problem. Make sure that you chose the right equation and that you copied all the data correctly.
 * Check that your answer has the right unit and the correct amount of significant figures.
 * You might need scientific notation in your answer. That is in Chapter 3.

Solving Conceptual Problems (Seamus Cuddy)

**Not every word problem in Chemistry requires calculations...** Conceptual Problems = Nonnumeric Problems <span style="display: block; font-family: helvetica,helvetica,sans-serif;">

**THE SOLVING:** __** Basics **__ Identify what is known and unknown, Make a plan to get from known to unknown ** __New For the Conceptual Problems__ ** No need to... Check the Units, Make an Estimate, or Check Your Calculations.

** Just Two Steps... ** 1) Analyze  2) Solve

<span style="display: block; font: 13px helvetica; letter-spacing: 0px; margin: 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">**Numerical Problems VS. Conceptual Problems:** <span style="display: block; font: 13px helvetica; margin: 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px; text-align: center;"> Numerical Problems require you to deal in numbers, doing things like converting measurements from unit to unit or rearranging an equation. Also, numerical problems require evaluating your answer if it is reasonable. Conceptual problems eliminate these numbers. You are required to solve a conceptual problem by just analyzing it and then solving it. It is very straightforward; right or wrong.

== Group 5 == Co-editor: Colleen Fitzgerald

Group Members: Colleen Fitzgerald and David O'Brien

Chapter 3 Section 1 (pages 63-72)

Using and Expressing Measurement


 * Measurement is a qualitative description that includes both a number and a unit.
 * - Units are usually measured acoording to the International System of Units (SI)
 * - Below is a chart of the SI base units and the quantities they measure for.

1. If it is a nonzero number its significant.
 * ~ Unit ||~ Symbol ||~  ||~ Measured Property ||
 * [|meter] || m ||, || length ||
 * [|kilogram] || kg ||  || mass ||
 * [|second] || s ||  || time ||
 * [|ampere] || A ||  || electric current ||
 * [|kelvin] || K ||  || thermodynamic temperature ||
 * [|mole] || mol ||  || amount of substance ||
 * [|candela] || cd ||  || luminous intensity ||
 * Scientific Notation: a given number is written as the product of two numbers- a coefficent and 10 raised to a power
 * The co-efficent must always be greater then 1 and less then 6
 * - Example- 602,000,000,000,000,000,000,000 = The coefficent would be 6.02 and then you would multiply 10 to the 23rd power
 * Accuracy, Prescision, and Error
 * Accuracy: the measure of how close a measurement comes to the actual or true value of whatever is being measured
 * Precision: the measure of how close a series of measure ments are to one another
 * For accuracy you must compare the measured value to the correct value
 * For precision you must compare two or more values of a repeated measurement
 * Example: Using Darts with Accuracy and Precision
 * 1. 3 darts land close together on the bullseye= good accuracy and precision
 * 2. 3 darts land near eachother but not on the bullseye= good precison but not accuracy
 * 3. 3 darts land far apart and not on the bullseye= poor accuracy and precision
 * Accepted Value: correct value based on reliable refrences
 * Experimental Value: value measured in a lab
 * Error= experimental value subtracted from the accepted value
 * Percent Error= Error didvided by the accepted value x 100%
 * Signinficant Figures in Measurement
 * Signinficant Figures: a measurement that includes all of the digits that are known, plus a last didgit that is estimated
 * Example: Something between 2.4 and 2.5 pounds might be 2.46. 2 and 4 are known with certainty but the 6 is estimated
 * Determining Significant Figures

2. Leftmost zeros that appear before nonzero didgits and are not significant

3. Zeros between nonzero numbers are significant.

4. Zeros at the end of a number and to the right of a decimal point are significant.

5. Zeros at the rightmost end of a measurement aren't significant.

6. Exact numbers have an unlimited number of siginificant figures.

Accuracy, Precision, and Error

David O' Brien

Rounding

1. Determine how many significant figures the number has.

2. Round to that many digits.

3. Drop the last significant figure if it is less then 5.

Rounding Answers in Addition & Subtraction Problems

1. Answers in these problems need to be rounded off.

2. You round the answer to the same number of decimal places, in the measurement taken with the least digits.

3. ex.) 36.231 + 63.43 + 18.6253 = 118.2863 (When rounded the answer comes to 118.27)

4. This is becasue the 63.43 only has two digits to the right of the decimal point which is the least in each factor of the equation so you round the answer to the same number of digits.

5. ex.) 42.389 - 31.36621 = 11.02279 (When rounded the answer comes to 11.023)

6. ex.) 6.2783 + 8.289 + 1.227 = 15.7943 (When rounded the answer comes to 15.794)

Rounding Answers in Multiplication & Division Problems

1. Answers from these problems need to be rounded off.

2. You round the answer to the same number of significant figures, in the measurement with the least number of significant figures.

3. ex.) 3.518 x .62 = 2.18116 (When rounded the answer comes to 2.18)

4. This is because the .62 has two significant figures which is the least amount of significant figures in both factors, so you use the same amount in your rounded answer.

5. ex.) 8.234 x 6.3417 = 52.2175578 (When rounded the answer comes to 52.217)

6. ex.) 10.586862 / 4.29 = 2.4678 (When rounded the answer comes to 2.47)

<span style="color: #010132; display: block; font-family: 'comic sans ms',cursive;"><span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">Group 6 <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">Co-editer: Marybeth Nametz <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">Group Members: Marybeth Nametz and <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">Alex Fischbach <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;"> <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">Section 3.2: The International System of Units (pgs 73-79)

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">The International System of Units <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">*Volume of any solid, liquid or gas(especially!) will change with temperature... <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">... to be accurate volume-measuring devices are taken at a given temperature-usually room temp. (20 degress Celsius)

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">Units of Mass

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Mass of an object is measure in comparison to a standard mass of 1 kg <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">-Kg: Basic SI unit of Mass <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Originally defined as the mass of 1 L of liquid water at 4 degree Celsius <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Gram: is 1/1000 of a kg <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- The mass of 1 cm3 of water at 4 degree Celsius is 1 gram <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Common Metric Units of Mass: include the kg, g, mg, and microgram <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Platform balance: measure mass of an object <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Beam balanced at level <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Unknown mass = sum of standard mass <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Analytical balance: Measures objects of less than 100g and determine mass to the nearest 0.1 mg <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Moon: weigh 1/6 of what you weigh on earth <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Gravity <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Weight: Measures the pull n a given mass by gravity <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Changes <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Mass: Measure of the quantity of matter <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Remains consistent

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;"> <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">Units of Temperature <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">Measure of how hot or cold an object is <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Determines the direction of heat transfer <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Heat transfers to the colder temperature <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Increase temperature: Objects expand <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Decrease: Contract (except water) <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Celsius: Sets the freezing point of water at 0 degrees Celsius and the boiling point of water at 100 degrees Celsius. <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Named after Anders Celsius <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Kevin Scale: The freezing point of water is 273.15 kelvins, and the boiling point is 373.15 K. <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- “Absolute scale” <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Lord Kevin <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Absolute zero = 273.15 degrees Celsius <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- A change of one degree on the Celsius scale is equal to one Kelvin on the Kelvin scale <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- K = C + 273 <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- C = K -273

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;"> <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">Units of Energy <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">Capacity to do work or to produce heat <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Joule and calorie are common units of energy <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Joule: SI unit of energy <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Cal: Quantity of heat that raises the temperature of 1 g of pure water by 1 degree Celsius. <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- 1J = 0.2390 cal <span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">-1 Cal = 4.184 J

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">Alex Fischback

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">Units of Mass

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Mass of an object is measure in comparison to a standard mass of 1 kg

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">-Kg: Basic SI unit of Mass

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Originally defined as the mass of 1 L of liquid water at 4 degree Celsius

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Gram: is 1/1000 of a kg

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- The mass of 1 cm3 of water at 4 degree Celsius is 1 gram

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Common Metric Units of Mass: include the kg, g, mg, and microgram

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Platform balance: measure mass of an object

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Beam balanced at level

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Unknown mass = sum of standard mass

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Analytical balance: Measures objects of less than 100g and determine mass to the nearest 0.1 mg

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Moon: weigh 1/6 of what you weigh on earth

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Gravity

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Weight: Measures the pull n a given mass by gravity

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Changes

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Mass: Measure of the quantity of matter

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Remains consistent

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Units of Temperature: Measure of how hot or cold an object is

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Determines the direction of heat transfer

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Heat transfers to the colder temperature

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Increase temperature: Objects expand

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Decrease: Contract (except water)

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Celsius: Sets the freezing point of water at 0 degrees Celsius and the boiling point of water at 100 degrees Celsius.

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Named after Anders Celsius

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Kevin Scale: The freezing point of water is 273.15 kelvins, and the boiling point is 373.15 K.

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- “Absolute scale”

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Lord Kevin

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Absolute zero = 273.15 degrees Celsius

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- A change of one degree on the Celsius scale is equal to one Kelvin on the Kelvin scale

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- K = C + 273

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- C = K -273

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Energy: Capacity to do work or to produce heat

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Joule and calorie are common units of energy

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Joule: SI unit of energy

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- Cal: Quantity of heat that raises the temperature of 1 g of pure water by 1 degree Celsius.

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">- 1J = 0.2390 cal

<span style="color: #010e32; font-family: 'Comic Sans MS',cursive;">-1 Cal = 4.184 J

=<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Group 7 = <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Co-Editor- Julia McNamara <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Group Members- Meghan Faber and Julia McNamara

===<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Conversion Problems p. 80-87 ===
 * <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">a conversion factor is a ratio of equivalent measures
 * <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">when a measure is multiplied by a conversion factor the numerical value is generally changed but the actual size is the same
 * <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">to form a ratio to convert a measure the larger unit is the numerator and the smaller measure is the denominator
 * <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">dimentional analysis is a way to analyze and solve a problem usins units of a measurment

<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Conversion Factors
<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">By: Julia McNamara <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">A conversion factor is a ratio of equivalent measurements.
 * <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">A quantity can be expressed in many different ways. (1 meter= 10 decimeters= 100cm= 100mm)
 * <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Whenever 2 measurements are equal, a ratio of the two measurements would equal 1
 * <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">measurements of the numerator=measurements of the denominator

<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">smaller number ---> 1 meter < larger unit <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">larger number ---> 100 cm < smaller unit


 * <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">When a measurement is multiplied by a conversion factor, the numerical value is generally changed, but the actual size of the quantity measured remains the same.

<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Dimensional analysis:
===<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Converting Between Units: === <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">By: Meghan Faber

<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">You can use dimensional analysis in a problem when you have to make the units in a problem the same.

====<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Converting Between Metric Units: ==== <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Example: Convert 750dg into grams.

====<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">First, Analyze: List what you do know and what you don't know. ==== <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Know- <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Mass=750dg <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">1 gram= 10dg

<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Don't know- <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Mass of 750dg in grams.

<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Since 10dg=1g, multiply the mass by the conversion factor: 1g/10dg (*Known unit in the denominator [bottom] and unknown is in the numerator [top])

====<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Second, Calculate: ==== <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">750dg X 1g/10dg = 75 g (Notice the "dg"'s cancel out)

====<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">*Make sure that the numbers make sense. For this problem, grams are bigger than decigrams (dg) so the mass number in grams should be less than in decigrams. (75<750 BUT 75g=750dg) ====

====<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Converting Between Metric Units with more than one conversion: ==== <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Example: Convert .073 cm into micrometers.

====<span style="color: #800080; font-family: 'Comic Sans MS',cursive;">First, Analyze: List what you know and what you don't know. ==== <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Know: <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">length= .073cm micrometers <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Since you need to go from centimeters to meters to micrometers, you need to make sure when you multiply, all of the units cancel out except for micrometers. <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Second, Calculate: <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">in scientific notation- 7.3 X 10^ -2 cm X 1m/10^2 cm X 10^6 micrometers/1m = 7.3 X 10^2 micrometers <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">not in scientific notation- .073cm X 1m/100cm X 1,000,000 micrometers/1m = 730 micrometers <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">(notice how meters and centimeters cancel out) <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">*Again, make sure the numbers make sense. For this problem, micrometers are smaller than centimeters, so the number of micrometers should be more than in centimeters. <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Converting Ratios of Units <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Converting ratios, is converting a set of two units. <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Example: Convert 7.21g/cm^3 to kg/m^3 <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">First, Analyze: List what you know and what you don't know. <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Know- <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">density=7.21g/cm^3 <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">10^3 (1,000) g/1kg <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">10^6 (1,000,000) cm^3 = 1m^3 <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Unknown- <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">density in kg/m^3 <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">In this problem, grams (g) needs to change to kilograms (kg), and centimeters (cm) needs to change to meters (m). <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">Second, Calculate: <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">in scientific notation: 7.21g/1cm^3 X 1kg/10^3g X 10^6cm^3/1m^3 = 7.21 X 10^3 kg/m^3 <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">not in scientific notation: 7.21g/1cm^3 X 1kg/1,000g X 1,000,000cm^3/1m^3 = 7,210 kg/m^3 <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">(again notice how the grams (g) and the centimeters (cm) are canceled out, leaving only kilograms (kg) and meters (m)) <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">*Finally make sure the numbers make sense. Since m^3 is a bigger volume than cm^3, the density in m^3 should be a larger number.

=<span style="color: #800080; font-family: 'Comic Sans MS',cursive;"> =

=<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Group 8 =

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Determining Density <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Co editor: Erika Paiva <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Members: Shannon Degnan and Erika Paiva <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Density and Temperature
 * <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">density is the ratio of mass to volume an object has
 * <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">density is an intensive property that depends only on the composition of a substance and how tightly packed the particles are

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Erika Paiva

====<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Clarifying Important Terms ====

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- Density is the ratio of an object's mass to its volume.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- Mass is the measure of the amount of matter that an object contains; the SI base unit for mass is the kilogram.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- Volume is a measure of the space occupied by a sample of matter.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- Shannon Degnan

===<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">The Key Concept === <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- The volume of most substances increases as the temperature increases.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- The mass remains the same despite the volume change and the temperature.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- The density of a substance generally decreases as its temperature increases.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- Density changes with temperature because the volume changes with temperature.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- When the temperature increases, The volume, the space occupied by the matter is getting bigger/increases, but the mass is staying the same, so it is becoming less dense.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- Over a certain range of temperature, the volume of water increases as its temperature decreases. Ice, or solid water, floats because it is less dense than liquid water.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;"> <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Calculating Density

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">mass- units g, kg, ect..

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">volume- units cm3, m3, ect...

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Density- units g/cm3, ect..

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;"> <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Problem:

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">A block of aluminum has a volume of 15.0 mL and a mass of 40.5 g. What is the density?

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;"> <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">1. Analyze:

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">list the known facts and the unknown.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Known

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- mass= 40.5 g

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- volume= 15.0 mL

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Unknown

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- density= ?

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;"> <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">2. Calculate:

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">solve for the unknown

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- substitute the known information and calculate.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">D= Mass/volume = 40.5 g/ 15.0 mL = 2.70 g/mL

=<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;"> = <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">3. Evaluate:

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">does this make sense?

= =

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Using Density to Calculate Volume

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- What is the volume of a pure silver coin that has a mass of 14 g? The density of a silver (AG) is 10.5 g/cm3.

= = <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;"> <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">1. Analyze:

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">List the knowns and the unknown.

= = <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Knowns

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Mass of coin = 14g

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Density of silver= 10.5 g/cm3

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Unkown

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Volume of coin= ? cm3.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- Solve this problem by using density as a conversion factor. You need to convert the mass of the coin into a corresponding volume. The density gives the following relationship between volume and mass.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">1 cm3 Ag= 10.5 g Ag

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- Notice that the known unit is in the denominator and the unknown unit is in the numerator.

=<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">= = <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;"> <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">2. Calculate:

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Solve for the unknown

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">- Multiply the mass of the coin by the conversion factor to yield an answer in cm3.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">14 g Ag X 1 cm3 Ag/ 10.5 g Ag= 1.3 cm3 Ag.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;"> <span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">3. Evaluate:

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">Does this make sense?

=<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">[|Density work sheet] =

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">1.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">a. 1.98 g/mL

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">b. 2 g/mL

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">c. 1.26 g/ mL

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">d. 7.8 X 10 ^-3 g/mL

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">e. 7.95 g/ml

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">2.

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">a. 3.54 ml

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">b. 316.6 ml

<span style="color: #420b42; font-family: 'Comic Sans MS',cursive;">The rest of the worksheet doesn’t pertain to the chapter, so don’t do the rest of the problems.