Bio Chapter 2 - Chemistry Of Life I

Front 1

Matter

Back 1

anything that has mass and occupies space.

Front 2

Elements

Back 2

pure chemical substance made of atoms with the same # of protons in their nuclei.

Front 3

Atomic Symbol

Back 3

shorthand method used for representing an element.

Front 4

Atomic Number

Back 4

number of protons in the nucleus of an atom.

Front 5

Atomic Mass

Back 5

the mass of the subatomic particles in an atom.

Front 6

Atoms

Back 6

smallest unit of matter non-divisible by normal chemical and physical means.

Front 7

Protons

Back 7

positively charged subatomic particles (inside the nucleus).

Front 8

Neutrons

Back 8

uncharged particles (inside the nucleus).

Front 9

Electrons

Back 9

negatively charged subatomic particles (outside the nucleus).

Front 10

Orbitals

Back 10

regions around the nucleus where electrons are likely to be found.

Front 11

Electron Shells

Back 11

orbitals are located here.

Front 12

Isotopes

Back 12

atoms of the same element with differing numbers of neutrons in their nuclei.

Front 13

Properties of Isotopes

Back 13

1. Many are unstable in the wild.

2. Lose energy by emitting small amounts of subatomic particles and/or radiation.

3. The time they exist is measured in half-lives.

Front 14

Molecules

Back 14

two or more atoms bonded together. Atoms may be either of same element or different ones.

Front 15

Compound

Back 15

atoms of two or more different elements bonded together.

Front 16

Chemical Bonds

Back 16

energy relationships between electrons.

Front 17

Valence Electrons

Back 17

electrons in the outermost energy shell.

Front 18

Octet Rule

Back 18

atoms are most stable when they have eight electrons in their outermost energy shell.

Exception: If it only has one outer shell, the it's full with two electrons.

Front 19

Ion

Back 19

charged atom.

Front 20

Ionic Bond (general)

Back 20

weak bond that is easily soluble in water. Atoms accept electrons to satisfy the Octet Rule, resulting in net electrical charge on the the atoms involved.

Front 21

Ionic Bond (charges)

Back 21

formed when ions of opposite charge are attracted to each other.

Front 22

Ionic Bond (ions)

Back 22

form when cation (+) bonds to an anion(-).

Front 23

Cation

Back 23

positively charged ion.

Front 24

Anion

Back 24

negatively charged ion.

Front 25

Covalent bond

Back 25

strong bond where atoms share electrons to satisfy the octect rule. Visually represented by dotted lines.

Front 26

Electronegativity

Back 26

the ability of an atom to attract electrons towards its nucleus when forming bonds with other atoms.

Front 27

Nonpolar Covalent Bond

Back 27

bond that forms between atoms of similar electronegativity. Electrons are shared equally between atoms. No partial charges.

Front 28

Polar Covalent Bonds

Back 28

bond that forms between atoms with different electronegativities. Electrons are not shared equally between atoms. Shared electrons are closer to the nucleus with greater electronegativity. Easily broken down in water.

Front 29

Hydrogen Bond

Back 29

a weak chemical attraction between a partial positively charged Hydrogen atom of one molecule and a partial negatively charged atom of another polar molecule.

Front 30

Properties of Hydrogen Bonds

Back 30

1. Easily broken.

2. Large numbers within a molecule add great stability.

Front 31

van der Waals Forces

Back 31

temporary, weak attractive forces which form between molecules.

Front 32

Free Radical

Back 32

molecule that has an atom with a single, unpaired electron in its outer shell. Steals electrons from other molecules and creates a new free radical.

Front 33

How Free Radicals Form

Back 33

1. Exposure to radiation or toxins

2. Response to disease-causing agents (in animals)

Front 34

Chemical Reaction

Back 34

when one or more substances are changed into other substances.

Front 35

Dehydration

Back 35

- removal of water

- joins 2 molecules

Front 36

Hydrolysis

Back 36

- addition of water to break molecule(s) apart.

Front 37

High Heat of Vaporization

Back 37

x5 as much energy is needed to vaporize water than to raise it from O degrees Celsius to 100 degrees Celsius.

Front 38

High Specific Heat

Back 38

the amount of heat energy that must be lost to lower temperature by 1 degree Celsius.

Front 39

Surface Tension

Back 39

Measure of the attraction between molecules at the surface of a liquid.

Front 40

High Heat of Fusion

Back 40

melting. Results in the molecules within the substance becoming more chaotic

Front 41

Colligative Properties

Back 41

properties that depend strictly on the total number of dissolved solutes, not on the specific type of solute. Boiling point; freezing point.

Front 42

Ice Floats

Back 42

ice floats because it's less dense than liquid water.