Chapter 1

Question 1

What is chemistry?

Answer 1

the study of matter, its properties, and the changes it undergoes

Question 2

What is matter?

Answer 2

anything that has mass and takes up space; 3 states: solid, liquid, gas

Question 3

What is a substance?

Answer 3

a substance has distinct properties and a composition that does not vary from sample to sample; 2 types: element, compound

Question 4

What is an element?

Answer 4

a substance that can NOT be decomposed to simpler substances; made up of a unique kind of atom, but can be made of more than one atom of that kind

Question 5

What is a compound?

Answer 5

a substance that CAN be decomposed to simpler substances because it is made up of more than one element; made of atoms from two or more elements

Question 6

What are atoms?

Answer 6

the building blocks of matter

Question 7

What are molecules?

Answer 7

groups of atoms

Question 8

What is the Law of Constant Composition?

Answer 8

states that compounds have a definite composition, meaning the relative number of atoms of each element in the compound is the same in any sample

Question 9

What is a heterogenous mixture?

Answer 9

a mixture that can VARY in composition throughout a sample

Question 10

What is a homogenous mixture?

Answer 10

a mixture with the same composition throughout the sample; EVENLY MIXED; aka a solution

Question 11

What are physical properties?

Answer 11

properties that can be observed WITHOUT CHANGING a substance into another substance (ex. color, odor, density, melting and boiling points, hardness)

Question 12

What are chemical properties?

Answer 12

properties that can only be observed when a substance is CHANGED into another substance (common ex. flammability - ability to burn in oxygen, a form of reactivity)

Question 13

What are intensive properties?

Answer 13

properties that are independent of the amount of the substance that is present (ex. density, boiling point, color); important for identifying a substance

Question 14

What are extensive properties?

Answer 14

properties that depend on the amount of the substance present (ex. mass, volume, energy)

Question 15

What are physical changes?

Answer 15

changes in matter that do NOT change the composition of a substance (ex. changes of state, temperature, and volume)

Question 16

What are chemical changes?

Answer 16

changes that result in new substances (ex. combustion, oxidation, decomposition)

Question 17

How can mixtures be separated?

Answer 17

based on physical properties of the components of the mixture; filtration, distillation, chromatography

Question 18

What is filtration?

Answer 18

solid substances are separated from liquids and solutions; based on different phases

Question 19

What is distillation?

Answer 19

uses differences in boiling points of substances to separate a homogenous mixture into its components; based on different boiling points

Question 20

What is chromatography?

Answer 20

separates substances on the basis of differences in the ability of substances to adhere to the solid surface; based on ability to adhere to a stationary phase

Question 21

What is energy?

Answer 21

capacity to do work or transfer heat

Question 22

What is work?

Answer 22

energy transferred when a force exerted on an object causes a displacement of that object

Question 23

What is heat?

Answer 23

the energy used to cause the temperature of an object to increase

Question 24

What is force?

Answer 24

any push or pull on an object

Question 25

What is kinetic energy?

Answer 25

the energy of motion

Question 26

What is potential energy?

Answer 26

stored energy; potential energy of an object depends on its relative position compared to other objects

Question 27

What are six basic types of energy?

Answer 27

chemical
heat
electrical
mechanical
light
nuclear

Question 28

What are the SI units (International System of Units)?

Answer 28

length - meter (m)
mass - gram (g)
temperature - Kelvin (K) or degrees Celsius
time - second (s)
amount of a substance - mole (mol) 6.022x10^(23) things
volume - cubic centimeter (cc, cm^3, or mL) or liter (L)

Question 29

What are these prefixes: mega, kilo, centi, milli, micro, nano?

Answer 29

mega - 1x10^6 - 1,000,000
kilo - 1x10^3 - 1000
centi - 1x10^-2 - 0.01
milli - 1x10^-3 - 0.001
micro - 1x10^-6 - 0.000001
nano - 1x10^-9 - 0.000000001

Question 30

What is the freezing point, boiling point, and density of water?

Answer 30

freezing point - 0 C / 32 F / 273 K
boiling point - 100 C / 212 F / 373 K
density - 1 g/mL

Question 31

How do you convert kelvin to Celsius?

Answer 31

K = C + 273

Question 32

How do you convert Celsius to Fahrenheit?

Answer 32

F = 9/5 C + 32

Question 33

What is the unit of energy?

Answer 33

Joule (J)

Question 34

What is an exact number?

Answer 34

a number that is counted or given by definition (12 eggs in 1 dozen)

Question 35

What is an inexact number?

Answer 35

a number that depends on how it was determined; scientific instruments have limitations and individuals can read some instrumentation differently; aka measured number

Question 36

What is precision?

Answer 36

a measurement of how closely individual measurements agree with one another

Question 37

What is accuracy?

Answer 37

a measurement of how closely individual measurements agree with the correct, or “true”, value

Question 38

What figures are significant?

Answer 38

1. all nonzero digits
2. zeroes between nonzero digits
3. zeroes at the beginning of a number are NEVER significant
4. zeroes at the end of a number are significant if it contains a decimal point

Question 39

How do you use significant figures in calculations?

Answer 39

+/- answers are rounded to least significant decimal place
multiplication/division answers rounded to same number of digits as the measurement with the fewest number of significant figures