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51 Cards in this Set
- Front
- Back
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Why is it important to report units with scientific measurements?
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scientists have to have a standard way of measuring information in order to be able to build off of and interpret it correctly. Without them it's hard to keep track of what's what.
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Why is it important to report a certain number of digits with scientific measurement?
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If they add additional zeroes such as .60 and .600 or if you round differentlyu the precision would be off. If you report more digits there's more precision... Fewer, less precisie
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Why is scientific notation necessary?
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necessary because too many zeros are cumbersome. It is easier to read if they are in scientific notation. Or to report significant figures. Allows the info to be written compactly.
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If a measured quantity is written correctly, which digits are certain? Which are uncertain?
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All except for the last digit are certain. The last digit is an estimate.
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Explain when zeros count as significant digits and when they do not.
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Zeros are significant if they are to the right of the decimal point at the end of the number and when they are between significant figures. THey aren't counted when they are at the end of the number or after the decimal point before the number.
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How many significant digits are in exact numbers? What kinds of numbers are exact?
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Exact numbers have an infinite number of significant figures. Exact numbers are those with no margin for error. Such as there are 60 minutes in 1 hour.
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What limits the number of significant digits in a calculation involving only addition and subtraction?
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The largest significant figure you can report is how many spaces to the right of the decimal the number goes.
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What limits the number of significant digits in a calculation involving only multiplication and division?
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The smallest number of sig. figs. makes the decision of how to report the number.
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What are the rules for rounding numbers?
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If the number is greater than or equal to 5 round up to the next highest number. If it is less than or equal to 5 you round down.
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How do significant figures work in calculation involving both addition/subtraction and multiplication/division?
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Do the part in brackets first. Make sure not to round till the very end to get the most precise measurement possible. keep track of how many digits you have during your calculations though.
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What are basic SI units? Length? Mass? Time? And Temperature?
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meter, kilogram, second, kelvin.
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What are common units of volume?
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1 liter=1000 ml.
1 liter= 1.057 quarts 1 US gallon-3.785 Liters. |
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Suppose you are trying to measure the diameter of a Frisbee. What unit and prefix multiplier yould you use?
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Unit= meter... centi
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What is the difference between mass and weight?
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The mass of an object is a measure of the quantity of matter within it, while the weight of an object is a measure of the gravitational pull on that matter. If you were weighed on mars you'd weigh less. Your mass would be the same.
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Why are units important in calculating?
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By themselves the numbers have little meaning. Units are always associated with its units otherwise it would confuse others who are looking at your work. The units must be followed to make sure the calculations are correct.
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How are units treated in a calculation?
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In a calculation they are treated as important they are used to make sure the problem isn't worked incorrectly. The solutions map uses them and cancells them out in the problem.
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What is a conversion factor?
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The quantity between the two values is the conversion factor. For example 2.54 cm = 1 inch.
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Why is the fundamental value of a quantity not changed when the quantity is multiplies by a conversion factor?
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They don't change it because they are equivalents.
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What is density? Explain why density can be a conversion factor. Between what quantities does it convert?
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it is a fundamental property of substances that differs from one substance to another. Its equation is D = M/V. It can be used to convert between mass and volume.
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Why does soda fizz?
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it is composed of tiny particals called atoms. They are bound together to form molecules the molecules that are fizzing are carbon dioxide and water. As long as the can is closed the carbon dioxide molecules remain mixed with the water molecules, held there by pressure. When the can is opened, the pressure is released the carbon dioxide molecules escape and as they do they create bubbles which causes the fizz.
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What are chemicals? Give some examples
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Everything is a chemical. Everything is made of atoms and molecules which are chemicals.
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what do chemists try to do? How do they understand the natural world?
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They are interested in why ordinary substances are the way they are. They try to understand the world using the scientific method, a way of learning that emphasizes observation and experimentation.
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Define Chemistry
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the science that seeks to understand what matter does by studying what atoms and molecules do.
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How is chemistry connected to everyday life? Is chemistry relevant only in the chemistry laboratory?
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Chemistry is all around us everything we experience is made up of atoms and molecules. It is useful to help us understand the world around us.
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Explain the scientific method.
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Step one make an observation. Step 2. hypothesize. Step 3. Test it using experiments. If it passes it may become a scientific law or if
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What is the difference between a law and a theory?
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A law synthesizes past observations and predicts future ones. A theory provides a broader and deeper explanation for observations and laws. They are more correct than laws.
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What is the difference between a hypothesis and a theory?
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A hypothesis is a tentative interpretation or explanation of the observations. Tehy are tested by observations. A number of similar observations leads to a scientific theory.
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What's wrong with the statement it's just a theory?
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Theories actually have the most data to back them up.
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What is the law of conservation of mass?
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The law of conservation of mass says in a chemical reaction matter cannot be created or destroyed it can only change forms.
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What is the atomic theory?
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The atomic theory explained the law of conservation of mass by proposing that all matter was compiosed of small indestructible particles called atoms.
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What are 3 things you need to do to succeed in this course?
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Chemistry requires curiosity and imagination, reuqires calculation, and requires committment.
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tera
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10 to the 12
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giga
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10 to the 9
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mega
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10 to the 6
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kilo
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10 to the 3
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deci
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10 to the negative 1
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centi
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10 to the negative 2
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million
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10 to the negative 3
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micro
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10 to the negative 6
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nano
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10 to the negative 9
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pico
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10 to the negative 12
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femto
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10 to the negative 15
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1km= ? miles?
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.6214 miles
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1 m= ?in ? yd
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39.37 in
1.094 yds. |
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1ft=?cm
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30.48cm
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1 in = ? cm
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2.54CM
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1kg= ? lbs?
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2.205lbs.
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1lb= ?g
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453.59 g
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1 oz= ?g
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28.35g
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1 liter= ?mL and ? cm cubed
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1000 of each
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1 gal=? L
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3.785 L
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