Chemistry 101 Exam 1

Front 1

Absolute Zero

Back 1

Lowest Temperature that is theorectically possible (0 K, 273.15 C, -459.67 F)

Front 2

alkali metals

Back 2

Group 1A of the periodic table. (lithium, sodium, potassium, rubidium, cesium, francium) Very reactive.

Front 3

alkaline metals

Back 3

Group 2A (Be, Mg, Ca, Sr, Ba, Ra)

Front 4

anion

Back 4

negatively charged atoms

Front 5

atom

Back 5

basic unit of a chemical element

Front 6

atomic mass

Back 6

mass of an atom of a chemical element. Equivalent to the number of protons + neutrons in an element.

Front 7

atomic number

Back 7

number of protons in a nucleus, which determines the chemical properties of an element.

Front 8

Bohr model

Back 8

arrangement of electrons around the nucleus of the atoms.

Front 9

cation

Back 9

positively charged atom

Front 10

Celsius scale

Back 10

scale of temperature which water freezes at 0 degrees and boils at 100.

Front 11

chemical change

Back 11

atoms/molecules are rearranged to produce different substances.

Front 12

chemical property

Back 12

change of the chemical nature of matter

Front 13

density

Back 13

mass per unity volume. (D=M/V, M=DxV, V=M/D)

Front 14

element

Back 14

building blocks of matter

Front 15

endothermic

Back 15

absorbs energy

Front 16

energy levels

Back 16

fixed amount of energy that a molecule, atom, electron or nucleus can have.

Front 17

entropy

Back 17

unavailability of a systems thermal energy for conversion into work; randomness in a system.

Front 18

exothermic

Back 18

heat is given off

Front 19

gas

Back 19

atoms/molecules are far distance apart, does not maintain shape or volume.

Front 20

gram

Back 20

metric unit of mass equal to one thousandth of a kilogram

Front 21

halogens

Back 21

reactive nonmetallic elements that form strongly acidic compounds with hydrogen

Front 22

heterogeneous mixture

Back 22

distinct layers

Front 23

homogeneous

Back 23

parts of all the same kind, uniform throughout.

Front 24

ion

Back 24

positively or negatively charged atoms

Front 25

isotope

Back 25

atoms of an element can vary in the number of neutrons

Front 26

kelvin

Back 26

absolute temperature scale

Front 27

1st law of thermodynamics

Back 27

Law of Conservation of Energy, energy cannot be created or destroyed during a chemical reaction. Energy is converted into useless forms: heat.

Front 28

Law of Conservation of Energy

Back 28

a chemical reaction is spontaneous when it increases the entropy of the universe.

Front 29

Law of Conservation of Matter

Back 29

atoms/molecules cannot be created or destroyed during a chemical reaction

Front 30

Law of Constant Composition

Back 30

a compound that is a pure substance contains the same elements in always the same exact proportions

Front 31

Law of Definite Proportions

Back 31

two or more elements may combine in a specific ratio to form a compound, the ratio never changes.

Front 32

Law of Multiple proportions

Back 32

two or more elements may combine in more than one proportion to form several different compounds. The starting reactants remain the same, the ratio will change.

Front 33

Liquid

Back 33

atoms/molecules that slip and slide over one another. Maintains volume, not shape.