Chapter 2

Front 1

Atoms

Back 1

The smallest unit of an element that contains all the characteristics of that element. They are the building blocks of matter.

Front 2

Electrons

Back 2

Subatomic particles that carries a negative (-) charge.

Front 3

Protons

Back 3

Subatomic particles that carries a positive (+) charge.

Front 4

Neutrons

Back 4

Subatomic particles that has no charge.

Front 5

Orbitals

Back 5

Lie at varying distances around the nucleus.

Front 6

Cation

Back 6

An atom having more protons than electrons has a net positive charge.

Front 7

Anion

Back 7

An atom having fewer protons than electrons carries a net negative charge.

Front 8

Isotopes

Back 8

Atoms of a single element that possess different numbers of neutrons.

Front 9

Oxidation

Back 9

During some chemical reactions, electrons are transferred from one atom to another and there is a loss of an electron.

Front 10

Reduction

Back 10

During some chemical reactions, electrons are transferred from one atom to another. In such reactions there is a gain of an electron.

Front 11

Redox reactions

Back 11

When the processes of oxidation and reduction are coupled, which often happens, one atom or molecule is oxidized while another is reduced in the same reaction.

Front 12

Octet rule

Back 12

Rule to describe patterns of chemical bonding in main group elements that require a total of eight electrons to complete their outer electron shell.

Front 13

Molecule

Back 13

A group of atoms held together in a stable association by energy.

Front 14

Compound

Back 14

When a molecule contains atoms of more than one element.

Front 15

Chemical bond

Back 15

The energy or force holding two atoms together in a molecule.

Front 16

Ionic bonds

Back 16

Form when atoms are attracted to each other by opposite electric charges.

Front 17

Covalent bonds

Back 17

Form when two atoms share one or more pairs of valence electrons.

Front 18

Double bonds

Back 18

Satisfies the octet rule by allowing two atoms to share two pairs of electrons.

Front 19

Single bonds

Back 19

Only one electron pair is shared.

Front 20

Electronegativity

Back 20

Atoms differ in their affinity for electrons and in general it increases left to right across a row of the periodic table and decreases down the column.

Front 21

Nonploar bonds

Back 21

For bonds between identical atoms the affinity for electrons is obviously the same and the electrons are equally shared.

Front 22

Polar covalent bonds

Back 22

A covalent bond in which electrons are shared unequally due to differences in electronegativity of the atoms involved.

Front 23

Polar molecule

Back 23

Has a net dipole as the result of opposing charges from polar bonds arranged asymmetrically.

Hint 23

Water is an example

Front 24

Hydrogen bond

Back 24

Polar molecules are attracted to one another, due to a special type of weak chemical bond. These bonds occur when the positive end of one polar molecule is attracted to the negative end of another.

Front 25

van der Waals forces

Back 25

Attraction between molecules in close proximity. Arises by transient dipole occurring in adjacent molecules.

Front 26

Chemical reactions

Back 26

The formation and breaking of chemical bonds.

Front 27

Enzymes

Back 27

In living systems these catalysts catalyze almost every chemical reaction.

Front 28

Surface tension

Back 28

A tautness of the surface of a liquid, caused by the cohesion of the molecules of liquid.

Front 29

Specific heat

Back 29

Defined as the amount of heat 1 g of a substance must absorb or lose to change its temperature by 1 degree Celsius.

Front 30

Heat of vaporization

Back 30

Defined as the amount of energy required to change 1 g of a substance from liquid to a gas.

Front 31

Hydrophobic

Back 31

"Water fearing" and describes nonpolar substances that are not soluble to water. Nonpolar molecules in water associate with each other and form droplets.

Front 32

Hydrophilic

Back 32

"Water loving" and describes substances that are soluble in water. These must be either polar or charged (ions).

Front 33

Hydrophobic exclusion

Back 33

The tendency of nonpolar molecules to aggregate together when placed in water. Exclusion refers to the action of water in forcing these molecules together.

Front 34

Mole

Back 34

Defined as the weight of a substance in grams that corresponds to the atomic masses of all of the atoms in a molecule of that substance.

Front 35

Acid

Back 35

Any substance that dissociates in water to increase the [H^+] (and lower the pH).

Front 36

Base

Back 36

A substance that combines with H+ when dissolved in water, and thus lowers the [H+].

Front 37

Buffer

Back 37

A substance that resists changes in pH and by releasing hydrogen ions when a base is added and absorbing hydrogen ions when acid is added, with the overall effect of keeping [H+] relatively constant.