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=Chapters 1 & 3= Editor: Caitlyn Vogt
 * Biology Period D**

1.1 Chemistry Zach Boulerice(co-editor) and Tess Murphy Chemistry- the study of the composition of matter and the changes that matter undergoes. Matter- anything that has mass and takes up space.
 * //What is Chemistry?//**

//Both living and nonliving things are made of matter, which means chemistry affects everything in life.//

//**Areas of Study**// There are five areas of study in Chemistry:
 * 1) organic chemistry- the study of all chemical containing carbon
 * 2) inorganic chemistry- the study of chemicals that generally do not contain carbon
 * 3) biochemistry- the study of processes that take place in organisms
 * 4) analytical chemistry- the area of study that focuses on the compostion of matter
 * 5) physical chemistry- the area that deals with mechanism, rate, and energy transfer that happens when matter undergoes change

//**Pure and Applied Chemistry**// Pure chemistry- the pursuit of chemical knowledge for its own sake. Applied chemistry- research that is directed toward a practical goal or application __Nylon:__
 * Hermann Staudinger, a German chemist, proposed that materials, like cotton and silk, are composed of small units all joing together like links in a chain.
 * In the early 1930s, Wallace Carothers tested Staudinger's proposal. His results supported the proposal. He produced materials not found in nature, like nylon.
 * Nylon- can be drown into into thin, long, silk-like fibers.[[image:http://prospect.rsc.org/blogs/cw/wp-content/uploads/2008/11/nylon_485.jpg width="190" height="147"]]
 * Natural silk was limited. A team of scientists and engineers applied Carother's research for commerical production of nylon.
 * In 1939, a large-scale method for making nylon fibers was perfected.

1.2 Chemistry Far and Wide Cassie Naimie (co-editor) and Erin Cropanese pgs. 12-19

Erin Cropanese(pgs. 12-15) **//Materials//** Chemists design materials to fit specific needs. **Macroscopic:** objects big enough to view with the unaided eye **Microscopic:** objects that can be seen only under magnification
 * George de Mestral of Switzerland patented the design for hook-and-loop tapes which was inspired when burrs got stuck to his clothing while hiking and he took a microscopic look at them

**//Energy//** Chemists play an essential role in finding ways to conserve energy, produce energy, and store energy. Conservation: -especially in homes and freezers Production: -these are called fossils fuels because they form the remains of ancient plants and animals Storage:
 * insolation
 * burning of coal, petroleum, and natural gas is a source of energy

-devices that use chemicals to store energy that will be released as electric current when the batteries are used <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">-cordless tools are a benefit of batteries <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">**//Medicine and Biotechnology//** <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">**//<span style="font-family: Arial,helvetica,sans-serif; font-size: 13px; font-style: normal; font-weight: normal; line-height: 19px;">Chemistry supplies the medicines, materials, and technology that doctors use to treat their patients. //** <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">Medicines: <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">Materials: <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">(burn patients may benefit from plastic "skin" that can heal itself when it cracks because chemicals are released from tiny capsules to repair it) <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">Biotechnology: <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">**Biotechnology:** applies science to the production of biological products or processes
 * <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">Batteries
 * <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">many drugs are effective because they interact in a specific way with chemicals in cells
 * <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">knowledge of structure and function of target chemicals helps a chemist design safe and effective drugs
 * <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">repair or replace body parts
 * <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">Scientists developed tools to aid them in the Human Genome Project which are used in biotechnology
 * <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">uses techniques that can alter DNA in living organisms[[image:http://www.ufgi.ufl.edu/images/7957genm-small.jpg width="280" height="223" align="right"]]
 * <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">Genes inserted into bacteria create chemicals (insulin)

<span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">**//Agriculture//** <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">Chemists help to develop more productive cr<span style="font-family: Arial,helvetica,sans-serif;">ops and safer, more effective ways to protect crops. <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">Productivity: <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">Crop Protection:
 * <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">track by measuring the amount of edible food grown on a given unit of land
 * <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">factors that decrease productivity are plant disease, lack of water, weeds, poor soil quality, and pests that eat them
 * <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">chemists can test the soils, conserve water, use biotechnology to develop plants more likely to survive drought or insect attack
 * <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">insecticides that used to be used to kill all insects even if they are useful because it was nonspecific is now designed to treat specific problems

Cassie Naimie(pgs. 16-19) __//**The Environment**//__ New technology has produced **pollutants** **Pollutant:** a material found in air, water, or soil that is harmful to humans or other organisms Examples:
 * Lead**-throughout history caused poisoning that led people to make bad decisions/ low levels of lead in the blood can permanently damage the nervous system


 * Pollutant Prevention:**
 * Lead paint has been banned
 * Lead in gas and water systems has been removed/banned
 * Blood tests are being done to determine lead levels

Since chemistry is the study of matter, chemists study matter brought back from space to make observations about the universe. //Discoveries://
 * //__The Universe__//**
 * 1868 Pierre Janssen discovered the gas on the sun's surface was not known on earth (at that time)
 * Norman Lockyer named the gas "helios" for the Greek word meaning "sun"
 * 1895 William Ramsay discovered helium on earth

__Section Assessment Questions:__ <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">8. When chemists develop new materials, what is their general goal? Chemist's general goal when designing new materials is to fit specific needs. <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">9. Name three ways chemists help meet the demand for energy. 1. Conservation- insolation 2. Production- burning fossils fuels 3. Storage- batteries <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">10.How do chemists help doctors treat patients? Chemists can come up with medicines and drugs that treat various conditions. They can also supply materials to replace or repair body parts. <span style="display: block; font: 13px/19px Arial; letter-spacing: 0px; margin: 0px;">11. What role do chemists play in agriculture? Chemists can make test soils to make sure they contain the best chemicals to grow the crop, use biotechnology to develop plants more likely to survive drought or insect attack, and conserve water. 12. How do chemists help protect the environment? Chemists help to identify pollutants and prevent pollution. 13. Desctibe two ways that chemists study the universe: 1.Chemists gather data from afar 2.Chemists analyze matter that is brought back to earth 14. Lead is a pollutant because low levels of lead in the blood can permanently damage the nervous system.

40% of all modern medicine comes from chemicals produced by plants and animals. To use nature as a source, chemists identify the ingredient and purify the chemical to make sure it is safe for humans to use. Chemists modify certain chemicals from nature to make them more effective and less harmful. Examples:
 * //__Nature's Pharmacy__//**
 * //Foxglove:// Poison that this plant produces is used to treat heart failure.
 * //Willow bark:// By 1828 chemists had isolated the active ingredient in willow bark that was previously made in to tea to treat headaches. For 70 years chemists worked on this chemical to produce the most effective drug. This drug is aspirin.
 * //Cone Snail:// These animals produce toxins that paralyze prey. Chemists are studying the toxins to treat chronic pain and Parkinson's disease.

=**//1.3 Thinking Like A Scientist-//** Sahana Nazeer (co-editor) and Henry Dodge pgs. 20-27=

__ Alchemy __
The word //chemistry// is derived from the word //alchemy//.

Alchemists studied matter.

Alchemy had a practical side (developing techniques for working with metals glass, and dyes) and a mystical side (concepts such as perfection).


 * Alchemists developed the tools and techniques for working with chemicals:**
 * Developed processes for separating mixtures and purifying chemicals
 * Designed equipment for the lab such as beakers, tongs, funnels, flasks, and mortar and pestle

Alchemists did not provide answers for the changes that they observed in matter.

__ An Experimental Approach to Science __ In the 1600s, some scientists formed the Royal Society of London for the Promotion of Natural Knowledge.

The aim of the society was to encourage scientists to use experimental evidence for any conclusions about the natural world and not philosophical debates.


 * In France, Antoine-Laurent Lavoisier helped to transform chemistry from a science of observation to a science of measurement, which it still is today. Lavoisier designed a balance to make careful measurements. **

How and Why do materials burn? Lavoisier was able to prove that oxygen is necessary for a material to burn.

__<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">The Scientific Method __

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">The scientific method is a three step progressive process to find the solution of a scientific problem. It consists of making observations, testing your hypothesis, and then developing theories. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;"> <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">The word “observation” is the process of observing and obtaining information. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">- making observations is a very attentive step because it deals of using all of your senses in addition to common sense <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">- you should be able to notice any changes, possibly record the data you monitor, and formulate a question based on your observations. <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; line-height: 115%;">**From your observations, you can formulate a question and your educated guess at the answer to your question.**

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Your proposed explanation for the question is called your hypothesis. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">- the second step of the scientific method deals with testing your hypothesis to see if it is accurate or not. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">- it is important to remember that your hypothesis has to answer the question based on the data you observed <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">-- if the experimental data does not fit the hypothesis, then the hypothesis has to be changed <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; line-height: 115%;">**You test your hypothesis by performing experiments** which is a procedure that is created to correctly test the hypothesis.

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">- These experimental procedures consist of: <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">1. the independent (manipulated) variable, which is changed during the experiment <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">2. the dependent (responding) variable, which is the variable that you observe and record the results of. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Before stating your hypothesis is correct however, it is required that no matter how many times anyone performs the experiment properly, the same result should occur.

<span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; line-height: 115%;">If your hypothesis does turn out to be correct and produce the same results no matter how many times the experiment is repeated, then it could become a theory.

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">A hypothesis is the proposed explanation for observations, but a theory is an explanation for a variety of observations that is well-tested. Although your theory could be well-tested and accurate, it can never be fully proved because in the future, there is always the possibility that the theory could be built on or changed to explain further observations. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;"> <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">The scientific method in example: <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">1. __<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Observation __<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">: I observe that my car will not start. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">2. __<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Hypothesis __<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">: **If** I put gas into my car, **then** my car will start. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Notice that the words “if” and “then” are bolded, because the proper way to state the hypothesis is to put the statement in the “if…then…” format. The first half, “if….” is the independent variable and the second half, “then…” is the dependent variable. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">3. __<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Experiment __<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">: I tested my hypothesis by putting gas in my car to see if my car will start. After following a certain procedure with the materials I need, I recorded the data the experiment produced. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">4. __R__ __<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">esult __<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">: My car started after putting gallons of gas in it. <span style="background: none repeat scroll 0% 0% yellow; font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Scientific laws <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;"> can be produced from numerous observations and experiments that repeatedly produce the same result; it is basically a statement that summarizes your results. __<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Collaboration and Communication __

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">//“Two heads are better than one.”// This statement holds true for all aspects of life, and it most certainly is applicable to science because the more scientists work together, then the more accurate and precise their results will be. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;"> Collaboration is merely when scientists work together, in order to combine the knowledge of various individuals from different fields on science if the research problems cannot be answered by just one person. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">They may work together because: <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">- __industries profiting__ from their investment in research by marketing applications that are produced from the research <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Working together might be tough, but the rewards received from the group’s work are worth much more. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">- when people work together, there is always some tension because if we all agreed, then there would not be such progress in the world today <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;"> <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;"> Communication is extremely significant for scientists because it makes sure that any ideas that are produced, proved, changed, or renewed are known by all in the field. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Over time, the way of communicating with others has changed due to technological advances. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">- from mail to journals, and now to electronical devices, the chance of error has **actually increased**. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">- the internet is an especially tricky place because all sorts of information can be posted on there. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">- __**the most reliable type of information is from scientific journals**__ <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">-- the use of journals date back a while ago, but they are still efficient because they are a firsthand source <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">--- to prevent an abundant amount of errors, the articles are reviewed before they are published. __<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">In order to be able to find the correct information, you must always consider the source. __

** __1.4 Problem Solving in Chemistry﻿﻿__ **
<span style="display: block; font-family: Georgia,serif;">Gr <span style="color: #000080; font-family: 'Comic Sans MS',cursive;">﻿ oup: Alex Trombetta(Co-editor) Gabriel Hannawi

**Key Concepts**

 * What is the general approach to solving a problem?
 * What are three steps for solving numeric problems?
 * What are the two steps for solving conceptual problems?

**__ Skills Used in Problem Solving (p. 28): __**
Problem solving is used in everything even with things as simple as which should I buy or which way is quicker. In order to problem solve you need a visual to refer to such as a graph, a data table, or another visual.

<span style="display: block; font-family: Georgia,serif;">- Effective problem solving always involves developing a plan and then implementing that plan.

**__ Solving Numeric Problems (pp. 29-30): __**
Almost all word problems in chemistry require math. These problems should be approached with a three step process.
 * 1) **Analyze** : One must first identify where they must start on the problem by identifying what is known and also where they are trying to get to which is the unknown. If the unknown is a number the units should be identified before the problem is started. Next, one must make a plan from getting from the known to the unknown. (ex: diagrams, graphs, tables, equations, etc.)
 * 2) **Calculate:** With a good plan calculations are the easiest. Sometimes in calculating you have to convert one unit to another or maybe rearrange the equation before you solve for the unknown.
 * 3) **Evaluate:** After determining the unknown and finding your answer you should evaluate to see if the answer makes sense, if the data is copied correctly, and if you chose the correct equations. Estimations is very helpful. Make sure then that your answer has correct units and also that it has the proper number of significant figures.

**Sample Problem**
You are visiting Indianapolis for the first time. Because it is a nice day, you decide to walk from Indiana State Capital to the Murat Centre for an afternoon performance. The shortest route to the capital is 8 blocks. how many minutes will it take if you can walk one mile in 20 minutes assuming that 10 blocks equals on mile. Knowns Unknown 2. **Calculate:** (Solve for the unknown) 8 block X __1 mile__ = 0.8 Miles
 * 1) **Analyze:** ( List the knowns and unknowns)
 * distance to be traveled= 8 blocks
 * walking speed= 1mile/20 minutes
 * 1mile=10 blocks
 * time of trip= ? minutes

10 blocks 0.8 Miles X __20 Minutes__ = 16 Minutes 1 Mile 3. **Evaluate:** (Does the result make sense? The answer seems reasonable, 16 minutes to walk 8 short blocks. The answer has the correct unit. The relationships used are correct.

** More Problems **
1.) Using the sample problem how many blocks can be walked in 48 minutes? 2.) There is an ice cream shop 6 blocks north of your hotel. How many minutes does it take you to get there and back?

**__ Solving Conceptual Problems (pp. 31-32): __**

 * non-numeric problems are conceptual
 * require you to apply concepts to things you're learning
 * two-step process for solving conceptual problems:
 * analyze-identify the relevant concepts
 * solve-apply concepts to the situation

__**Using and Expressing Measurements**__

 * __Measurement-__ A quantity represented by a number and a unit. They are fundamental to the experimental process. One must be able to make measurements and decide if each measurement is correct.
 * Often in chemistry, you will deal with extremely large or small numbers, such as 372,000,000,000 or 0.00000000062. Such numbers can be inconvenient to write down and use. To make this easier, chemists use __scientific notation.__
 * __Scientific Notation-__ To write a large number in scientific notation, rewrite it as a coefficient multiplied by 10 raised to a power. For example:

372,000,000,000 becomes 3.72000000000. The end result is 3.72 x 10^11
====To write a number in scientific notation, rewrite the number so it is less than 10, but greater than or equal to 1 by moving the decimal place. The number of places the decimal moved is the power to which 10 is raised, in this case 11.====

**__Accuracy, Precision, and Error__**

 * __Accuracy__ - This is the measure of how close your measurement was to the accepted, true, or correct value. If you were to mass a 5g block and measured 10g, your accuracy would be poor. If you were to measure 4.9g, your accuracy would be good.
 * __Precision -__ Precision is related to accuracy but is not the same thing. Precision is the measure of how close measurements of several experiments are to one another. If you're measurements over several tests were 4g, 4.5g, and 4.3g, your precision would be doing well. However, measurements of 3g, 10g, and 8g show poor precision, as them measurements aren't very similar.
 * You can have poor accuracy but good precision.If the true value was 5g, and you had three measurements of 10g, 10.4g, and 10.2g, you would have good precision; the measurements are close to one another, but poor accuracy; the measurements are not reflective of the true value.
 * __Accepted Value -__ The measurement of something generally accepted as its actual value.
 * __Experimental Value-__ The measurement you found through experimentation.
 * __Error -__ Error represents the difference between your experimental value and the accepted value of a measurement. To find the error, find the difference(subtract) between your experimental value and the accepted value. The percent error is the error converted into a percent. To do this, divide the absolute value of the error by the accepted value, then multiply by 100%.

**__Significant Figures in Measurements__**

 * When measuring values, you can estimate the next smallest decimal place past what is measurable with a tool. Say you weighed something that is read to be between 2.4 lb and 2.5 lb on a scale that can read to the nearest 10th. It is acceptable to estimate the hundredths place. 2.46 lb would be an estimate. Although only the 2 and .4 are a certainty, the estimated place has useful information too. All these numbers are the
 * __Significant Digits -__ All digits known in a measurement, plus one last digit that is estimated. These are useful in mathematic calculations that require a certain number of digits.

Kevin McAllister-pgs 67-72 1 2 . 5 2 meters 3 4 9 . 0 meters __X 8. 2 4__ meters 3 6 9 . 7 6 The non rounded answer of this problem comes out to 369.76, but using what we know about addition and sig figs, we need to round to only one decimal place because 349.0 has only one decimal place. The answer using Significant figures is 369.8 meters
 * __Rules for Determining Whether a Digit in a Measured Value is Significant__**
 * 1) Every number that is not zero (0) in a measurement is significant. Whether it is 31.8, 0.715, or 645, it is measured to three significant figures.
 * 2) Zeros **BETWEEN** nonzero numbers are significant. Example: 11.709. The 0 is a significant because its between.
 * 3) Zeros **IN FRONT OF** nonzero numbers are <span style="font-family: 'Arial Black',Gadget,sans-serif;">NOT Significant because they are simply placeholders. Scientific Notation can be used to eliminate placeholders
 * 4) Zeros **AT THE END** of numbers and **TO THE RIGHT** of the decimal point are **__ALWAYS__** Significant figures
 * 5) Zeros that lie **TO THE RIGHT** of the end of the number but **IN FRONT OF** a decimal point (which is not technically needed because this only deals with whole numbers) are <span style="font-family: 'Arial Black',Gadget,sans-serif;">NOT Significant figures because they are just placeholders.
 * 6) An unlimited number of Significant figures is present in 2 cases. The first is Counting. When you get to a number, say 24, there is an infinite number of significant figures. The other example is when you have conversions such as 60 min=1 hr. These have infinite significant figures also.
 * 7) Check out[|THIS VIDEO] to learn more about the zeros in significant figures.
 * __Significant Figures in Calculations__**
 * If you had a problem where you needed to multiply two numbers each rounded to 2 significant figures (such as 7.7 meters and 5.4 meters), the answer will come out to four significant figures (41.58 square meters). The problem with this is that the answer to a problem should never be more specific than the original numbers being multiplied. The easy fix for this is just to make the answer into 2 significant figures. Instead of 41.58 square meters, the problem is estimated to 42 square meters
 * In order to round numbers, you need to know how many significant figures are needed. Once you find that out, you know to only round to that number. The actual rounding part is simple. If the next digit after you cut off is 5 or above, round the last digit up. If it is below five, round it down.
 * For addition and subtraction, your answer should be rounded to the same number of **DECIMAL PLACES** as the number with the least amount of decimal places. See Example 1
 * For multiplication and division, the answer should be rounded to the number of **SIGNIFICANT FIGURES** of the number being multiplied or divided with the least amount of Sig Figs. The decimal point when doing multiplication or division doesn't matter because you are measuring Significant Figures not Decimal places like you are in addition. See Example 2
 * __EXAMPLES FOR USING SIGNIFICANT FIGURES__**
 * 1.)**

7 . 5 5 meters (X) __0. 3 4 meters__ 2 . 5 6 7 square meters The non rounded answer comes out to 2.567 square meters but because 0.34 has only two significant figures, the answer must be rounded to only two significant figures. Instead of 2.567, the Estimated Answer becomes 2.6 square meters 2 . 4 5 2 6 meters (/) __8 . 4 meters__ 0 . 2 9 1 9 7 6 meters The non rounded answer comes out to 0.291976 but we need to round to only two significant figures because of 8.4 is only two sig figs. The estimated answer would actually be 0.29 meters which is a lot easier to work with than the actual answer.
 * 2a.)**
 * 2b.)**

[|USE THIS GAME TO HELP WITH SIG FIGS!!!!!!!!!!]

//3.2 The International System of Units-// 6. Jess Mahoney, pages 73-75 and Lauren Sachs (Co-editor), pages 76-79
__**Measuring with SI Units**__
 * units are used in all measurements as reference points
 * the standard units of measurements in science are from the metric system
 * the **metric system** is easy to use because it's based on multiples of 10
 * **International System of Units**- SI is the revised version of the metric system, and was adopted by internation agreement in 1960
 * there are 7 base units
 * the 5 most commonly used in chemistry:
 * meter : unit of length~ symbol: m
 * kilogram: unit of mass~ symbol: kg
 * kelvin: unit of temperature~ symbol: K
 * second: unit of time~ symbol: s
 * mole: amount of a substance~ symbol: [[image:metric_prefixes.gif width="463" height="201" align="left"]]

1 kilometer= 5 city blocks 1 meter= the distance from the doorknob to the floor 1 centimeter= the width of a shirt button 1 millimeter= the thickness of a dime 1 liter= 1 quart of milk 1 milliliter= 20 drops of water 1 cubic centimeter= 1 cube of sugar
 * __Units and Quantities__**
 * Length- SI's basic unit: **meter**
 * smaller and larger distances may need prefixes
 * larges distances, for example, usually are expressed in kilometers. (1000 meters)
 * smaller distances are expressed in units such as decimeters (10 times smaller than a meter) or a centimeter (100 times smaller than a meter)
 * common units of length in the metric system: **centimeter, meter, and kilometer**
 * __Units of Volume__**
 * //What is volume?// **volume** is the space occupied by matter
 * //Why is the unit of volume based on units of length?// because the volume of a cube is length times width times height
 * //What is the liter?// **liter** is a non-SI unit that is convenient to use daily. It's the volume of a cube whose volume is 10^3. It's also equal to 1 cubic decimeter because a decimeter is 10 cm too.
 * Common metric units of volume: **liter, milliliter, cubic centimeter, and microliter**
 * //What are some devices to measure liquids in?// graduated cylinders, pipets, burets, syringes, volumetric flasks
 * **important note:** the volume of any matter will change with temperature change
 * Some (approximated) comparisons that might help:**

__**Units of Mass (pg. 76)**__
 * **Mass** is the measure of the amount of matter an object contains
 * The base unit of mass is the **kilogram (kg)**
 * A **kilogram** is the mass of 1 liter of water when it is at the temperature of 4 degrees Celsius (39.2 degrees Fahrenheit)[[image:http://t1.gstatic.com/images?q=tbn:ANd9GcSe_5rLyix0HEh_DhaFLyiTKF76ODUYaX3JjCr6SwOULZjF_kE&t=1&usg=__Yfq0C_NievBCxj77K4WthCzMbn8= width="251" height="201" align="right"]]
 * there are 1,000 grams in a kilogram
 * **Weight** is the amount that gravity pulls on an object's mass
 * Therefore, weight changes, but mass doesn't
 * = **__Metric Units of Mass__**  ||
 * = **Unit**  ||=  **Relationship**  ||=  **Example**  ||
 * = **Kilogram (kg)**  ||=  1 kg = 10^3g  ||=  small textbook  ||
 * = **Gram (g)**  ||=  1 g = 10^-3 kg  ||=  dollar bill  ||
 * = **Milligram (mg)**  ||=  10^3 mg = 1 g  ||=  ten grains of salt  ||
 * = **Microgram (µg)**  ||=  10^6 µg = 1 g  ||=  particle of baking powder  ||

Conversion Practice K = degrees C + 273.15 Degrees C = K - 273.15 Celsius to Kelvin calculator Converting between temp. scales practice
 * __Units o__****__f Temperature (pg. 77)__**[[image:http://www.clker.com/cliparts/9/b/f/c/11954269811233721818celsius_kelvin_ralph_kle_02.svg.med.png width="117" height="205" align="right"]]
 * **Temperature** is a measure of how hot or cold an object is
 * Most substances expand when heated and contract when cooled off (water is an exception)
 * Heat moves from an object at a higher temp. to one at a lower temp. at contact
 * Two temperature scales are commonly used by scientists: the **Celcius scale** and the **Kelvin scale**
 * The **Celsius scale** sets the freezing point of water at zero degrees and the boiling point at one hundred degrees
 * The **Kelvin scale (K)** is named for Lord Kelvin
 * The boiling point is 373.15 K and the freezing point is 273.15 K
 * **Absolute zero** (or 0 K) is -173.15 degrees Celsius and is the lowest temperature that can be reached


 * __Units of Energy (pg. 79)__**
 * **Energy** is the capacity to do work or produce heat
 * The **joule** and the **calorie** are ways to measure energy
 * The **joule (J)** is part of the international system of measurement
 * A **calorie (cal)** will raise 1 gram of pure water 1 degrees Celsius

1 J =0.2390 cal 1 cal = 4.184 J Energy unit conversion calculator =



**3.3 Conversion Problems** By: Nicky Romero (co-editor) and Chris Hughes? CHRIS DELETE THIS WHEN YOU DO YOUR PART! __**Conversion Factors**__ By: Nicky Romero


 * **A Conversion Factor** - a ratio of equivalent measurements.
 * In a conversion factor, the measurement in the numerator is equivalent to the measurement in the denominator.
 * Conversion factors are useful in solveing problems in which a given measurement must be expressed in some other unit of measure.
 * **When a measurement is multiplieed by a conversion factor, the numerical value is generally changed, but the actual size of the quantity measured remains the same.**
 * (smaller number) (larger unit) **/** (larger number) (smaller unit)



__**Dimensional Analysis**__

By: Nicky Romero


 * **Dimensional analysis-** a way to analyze and solve problems using the units, or dimensions, of the measurements.

STEPS of DIMENSIONAL ANALYSIS: **Dimensional analysis provides you with an alternatice approach to problem solveing.** There is usually more than one way to solve a problem. . 3.4- __Density__ =
 * 1) Analyze: list the knowns and the unknown
 * 2) Calculate: Solve for the unknown
 * 3) Evaluate: Does the result make sense?

By: Joe Hatch (co-editor) and Andrew Ware

 * __Determining Density__**
 * Density is found by dividing an objects mass by its volume; it is a ratio
 * Example: 10 grams of lead has a volume of 0.88 cm^3, so its density would be 11.4 g/cm^3
 * Density only depends on the composition of the subject, and not the size of the sample
 * This means that 100 grams of water would still have the same density of 1 gram of water
 * Obviously, solutions that are more dense than others will sink if in a container with a less dense solutions
 * Example: corn oil will float on top of corn syrup if in a container together




 * __Density and Temperature__**
 * The volume of most substances increases as the temperature increases, but the mass will stay the same
 * Since density is the ratio of an object's mass to its volume, the density could change
 * The density of a substance usually decreases as its temperature increases
 * Water is an exception to this rule, it does the opposite



__<span style="font-family: Arial,Helvetica,sans-serif;">Calculating Density __
__<span style="font-family: Arial,Helvetica,sans-serif;">STEP 1: ANALYZE – list out what is known and unknown. __
 * <span style="font-family: Arial,Helvetica,sans-serif;">If a copper penny’s density is 3.1g and it’s volume is 0.35cm3. What is the density of the copper?

<span style="font-family: Arial,Helvetica,sans-serif;">-Mass = 3.1g -Volume = 0.35cm3 UNKNOWN: -Density = ?g/cm3
 * <span style="font-family: Arial,Helvetica,sans-serif;">KNOWN:

<span style="font-family: Arial,Helvetica,sans-serif;">__STEP 2: CALCULATE – Solve for what is unknown__. <span style="font-family: Arial,Helvetica,sans-serif;">Density = Mass/Volume = 3.1g/0.35cm3 = 8.8571g/cm3 __<span style="font-family: Arial,Helvetica,sans-serif;">STEP 3: Does the final result make sense? __
 * <span style="font-family: Arial,Helvetica,sans-serif;">To determine the density use the known variables and this definition of density: Density = Mass/Volume
 * <span style="font-family: Arial,Helvetica,sans-serif;">To solve for the unknown, substitute the values that are known for the mass and volume, then calculate the density.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Round to two significant figures – 8.9g/cm3
 * <span style="font-family: Arial,Helvetica,sans-serif;">A piece of copper having a volume of about 0.3cm3 has a mass of about 3 grams. Therefore, about 3 times that volume of copper, 1cm3, should have a mass of about 3 times larger – about 9 gram. This estimate agrees with the solution we calculated.

__<span style="font-family: Arial,Helvetica,sans-serif;">Using Density to Calculate Volume __

 * <span style="font-family: Arial,Helvetica,sans-serif;">What would the volume of a pure silver coin be, if the coin has a mass of 14g? The density of silver is 10.5g/cm3.

__<span style="font-family: Arial,Helvetica,sans-serif;">STEP 1: ANALYZE – list out what is known and unknown. __


 * <span style="font-family: Arial,Helvetica,sans-serif;">KNOWN:
 * <span style="font-family: Arial,Helvetica,sans-serif;">Mass of coin = 14g
 * <span style="font-family: Arial,Helvetica,sans-serif;">Density of silver = 10.5g/cm3
 * <span style="font-family: Arial,Helvetica,sans-serif;">UNKNOWN:
 * <span style="font-family: Arial,Helvetica,sans-serif;">Volume of coin = ?cm3
 * <span style="font-family: Arial,Helvetica,sans-serif;">To solve this problem use density as a conversion factor. You need to convert the coin’s mass into a corresponding volume. The Density will give the following relationship between volume and mass.
 * <span style="font-family: Arial,Helvetica,sans-serif;">1cm3 AG = 10.5g AG


 * <span style="font-family: Arial,Helvetica,sans-serif;">Based on this, you can form the following conversion factor:
 * <span style="font-family: Arial,Helvetica,sans-serif;">1cm3 AG/10.5g Ag

<span style="font-family: Arial,Helvetica,sans-serif;">__STEP 2: CALCULATE – Solve for the unknown__.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Notice how the known unit is the denominator and the unknown is the numerator.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Multiply the mass by the conversion factor to form an answer in cm3.
 * <span style="font-family: Arial,Helvetica,sans-serif;">14g AG 1cm3 AG/10.5g AG = 1.3cm3 AG

__<span style="font-family: Arial,Helvetica,sans-serif;">STEP 3: EVALUATE – Does the answer make sense? __
 * <span style="font-family: Arial,Helvetica,sans-serif;">It makes sense that 14g of silver should have a volume slightly larger than 1cm3 because a mass of 10.5g of silver has a volume of 1cm3