Ch. 2 - Atoms, Molecules, And Ions

Front 1

Acid

Back 1

a substance that provides H+ ions when dissolved in water

Front 2

Anion

Back 2

a negatively charged atom or group of atoms

Front 3

Atom

Back 3

the smallest particle that retains the chemical properties of an element

Front 4

Atomic mass

Back 4

the weighed average mass of an element’s atoms

Front 5

Atomic mass unit (amu)

Back 5

a convenient unit of mass; 1/12th the mass of a 12-6 C atom

Front 6

Atomic number (Z)

Back 6

the number of protons in an atom’s nucleus

Front 7

Base

Back 7

a substance that provides OH- ions when dissolved in water

Front 8

Cathode ray

Back 8

the visible glow emitted when an electric potential is applied between two electrodes in an evacuated chamber

Front 9

Cation

Back 9

a positively charged atom or group of atoms

Front 10

Chemical bond

Back 10

the forces that hold atoms together in chemical compounds

Front 11

Chemical equation

Back 11

a format for writing a chemical reaction, listing reactants on the left, products on the right, and an arrow between them.

Front 12

Chemical reaction

Back 12

the transformation of one substance into another

Front 13

Covalent bond

Back 13

a bond that occurs when two atoms share several (usually two) electrons

Front 14

Element

Back 14

a fundamental substance that can’t be chemically changed or broken down into anything simpler

Front 15

Homogenous mixture

Back 15

a mixture having a constant composition

Front 16

Chemical formula

Back 16

a format for listing the number and kind of constituent elements in a compound

Front 17

Electron

Back 17

a negatively charged, fundamental atomic particle

Front 18

Heterogenous mixture

Back 18

a mixture having regions with differing compositions

Front 19

Ion

Back 19

a charged atom or group of atoms

Front 20

Ionic bond

Back 20

a bond that results from a transfer of one or more electrons between atoms

Front 21

Ionic solid

Back 21

a solid whose constituent particles are ions ordered into a regular 3-D arrangement held together by ionic bonds

Front 22

Isotope

Back 22

atoms with identical atomic numbers but different mass numbers

Front 23

Law of definite proportions

Back 23

different samples of a pure chemical substance always contain the same proportion of elements by mass

Front 24

Law of mass conservation

Back 24

mass is neither created nor destroyed in chemical reactions

Front 25

Law of multiple proportions

Back 25

the mass ratios are small, whole-number multiples of one another when two elements combine in different ways to form different substances

Front 26

Mass number (A)

Back 26

the total number of protons and neutrons in an atom

Front 27

Mixture

Back 27

a blend of two or more substances in some random proportion

Front 28

Molecule

Back 28

the unit of matter that results when two or more atoms are joined by covalent bonds

Front 29

Nucleus

Back 29

the central core of an atom consisting of protons and neutrons

Front 30

Oxoacid

Back 30

an acid that contains oxygen in addition to hydrogen and another

Front 31

Neutron

Back 31

a neutral, fundamental atomic particle in the nucleus of atoms

Front 32

Oxoanion

Back 32

an anion in which an atom is combined with oxygen

Front 33

Polyatomic ions

Back 33

a charged, covalently bonded group of atoms

Front 34

Proton

Back 34

a positively charged, fundamental atomic particle in the nucleus of atoms

Front 35

Structural formula

Back 35

a representation that shows the specific connections between atoms in a molecule

Front 36

Chemical compound

Back 36

a pure substance that is formed when atoms of two or more different elements combine and create a new material with properties completely unlike those of its constituent elements

Front 37

Heterogeneous mixture

Back 37

a mixture having regions with differing compositions

Front 38

Neutron

Back 38

a neutral, fundamental atomic particle in the nucleus of atoms