Biology Vocabulary From Chapter 4

Front 1

Acid

Back 1

compund that donates H+ ions to an aqueous solution and measures less than 7 on the pH scale

Front 2

Adhesion

Back 2

attraction between unlike molecules

Front 3

Aqueous Solution

Back 3

solution in which water is the solvent

Front 4

Atom

Back 4

smallest particle of an element

Front 5

Atomic Number

Back 5

number of protons in an atom’s nucleus; is unique for each element

Front 6

Base

Back 6

compound that removes H+ ions from an aqueous solution and that measures more than 7 oh the pH scale

Front 7

Buffer

Back 7

substance that maintains a fairly constant pH in a solution by accepting H+ ions when their levels rise and donation H+ ions when their levels fall

Front 8

Chemical Reaction

Back 8

breaking of old and formation of new chemical bonds that result in new substances

Front 9

Cohesion

Back 9

tendency of molecules of the same kind to stick to one another

Front 10

Compound

Back 10

substance containing two or more elements chemically combined in a fixed ratio

Front 11

Covalent Bond

Back 11

chemical bond that forms when two atoms share electrons

Front 12

Electron

Back 12

subatomic particle with a single unit of negative electric charge (-)

Front 13

Element

Back 13

pure substance that cannot be broken down into other substances by chemical or physical means

Front 14

Hydrogen Bond

Back 14

bond created by the weak attraction of a slightly positive hydrogen atom to a slightly positive negative portion of another molecule

Front 15

Ion

Back 15

atom that has become electrically charged as a result of gaining or losing an electron

Front 16

Ionic Bond

Back 16

chemical bond that occurs when an atom transfers an electron to another atom

Front 17

Isotope

Back 17

one of several forms of an element, each containing the same number of protons in their atoms but a different number of neutrons

Front 18

Matter

Back 18

anything that occupies space and has mass

Front 19

Molecule

Back 19

two or more atoms held together by covalent bonds

Front 20

Neutron

Back 20

subatomic particle that has no charge (is electrically neutral)

Front 21

Nucleus

Back 21

is an atom, the central core that contains protons and neutrons; in a cell, the part that houses the cell’s genetic material in the form of DNA

Front 22

pH Scale

Back 22

a range of numbers used to describe how acidic or basic a solution is; ranges from 0 (most acidic) to 14 (most basic)

Front 23

Polar Molecule

Back 23

molecule in which opposite ends have opposite electric charges

Front 24

Product

Back 24

material created as a result of a chemical reaction

Front 25

Proton

Back 25

subatomic particle with a single unit of positive electric charge (+)

Front 26

Radioactive Isotope

Back 26

isotope in which the nucleus decays (breaks down) over time, giving off radiation in the form of matter and energy

Front 27

Reactant

Back 27

starting material for a chemical reaction

Front 28

Solute

Back 28

substance in a solution that is dissolves the other substance and is present in the greater amount

Front 29

Solution

Back 29

uniform mixture of two or more substances

Front 30

Solvent

Back 30

substance in a solution that is dissolves the other substance and is present in the greater amount

Front 31

Temperature

Back 31

measure of the average energy of random motion of particles in a substance

Front 32

Thermal Energy

Back 32

total amount of energy associated with the random movement of atoms and molecules in a sample of matter

Front 33

Trace Element

Back 33

element critical to health that makes up less than 0.01 percent of body mass