Biology Chapter 2

Front 1

anything that occupies space and has mass

Back 1

matter

Front 2

the quantity of matter an object has

Back 2

mass

Front 3

the force produced by gravity acting on mass

Back 3

weight

Front 4

substances that cannot be broken down chemically into simpler kinds of matter

Back 4

elements

Front 5

chart that summarizes information about the elements

Back 5

periodic table

Front 6

simplest particle of an element that retains all of the properties of that element

Back 6

atom

Front 7

the central region of an atom; makes up the bulk of an atom; consists of two kinds of subatomic particles

Back 7

nucleus

Front 8

positively charged subatomic particle; the number of these becomes an element's atomic number

Back 8

proton

Front 9

this subatomic particle has no charge

Back 9

neutron

Front 10

the number of protons in an atom

Back 10

atomic number

Front 11

number that is equal to the total number of protons and neutrons in an atom

Back 11

mass number

Front 12

negatively charged subatomic particles in an atom

Back 12

electrons

Front 13

three dimensional region around a nucleus that indicates the probable location of an electron and correspond to specific energy levels

Back 13

orbital

Front 14

atoms of the same element that have a different number of neutrons

Back 14

isotopes

Front 15

takes into account the relative amounts of each isotope in the element, and this average is the mass found in the periodic table

Back 15

average atomic mass

Front 16

made up of atoms of two or more elements in fixed proportions

Back 16

compounds

Front 17

elements that do not react with other elements under normal conditions

Back 17

noble/inert elements

Front 18

the attractive formces that hold atoms together

Back 18

chemical bonds

Front 19

forms when two atoms share one or more pairs of electrons

Back 19

covalent bond

Front 20

the simplest part of a substance that retains all of the properties of that substance and can exist in a free state

Back 20

molecule

Front 21

the attraction between positive and negative electrical charges

Back 21

ionic bond

Front 22

an atom or molecule with an electrical charge

Back 22

ion

Front 23

the ability to do work

Back 23

energy

Front 24

one or more substances change to produce one or more different substances

Back 24

chemical reaction

Front 25

substance or molecule that participates in a chemical reaction

Back 25

reactants

Front 26

substance that forms in a chemical reaction

Back 26

products

Front 27

sum of all chemical processes that occur in an organism

Back 27

metabolism

Front 28

the amount of energy needed to start a chemical reaction

Back 28

activiation energy

Front 29

chemical substances that reduce the amount of activation energy that is needed for a reaction to take place

Back 29

catalyst

Front 30

a protein or rna molecule that speeds up metabolic reactions without being permanently changed or destroyed

Back 30

enzyme

Front 31

oxidation-reduction reaction;
reaction in which electrons are transferred between atoms

Back 31

redox reactions

Front 32

reaction in which a reactant loses one or more electrons, becoming positive in charge

Back 32

oxidation reaction

Front 33

reaction in which a reactant gains one or more electrons, becoming negative in charge

Back 33

reduction reaction

Front 34

compound with an uneven distribution of charge

Back 34

polar

Front 35

the force of attraction between a hydrogen molecule with a partial or full negative charge

Back 35

hydrogen bond

Front 36

attractive force that holds molecules of a single substance together

Back 36

cohesion

Front 37

molecules at the sruface of water are pulled downward, and the water acts as if it has a thin 'skin'

Back 37

surface tension

Front 38

attractive force between two particles of different substances

Back 38

adhesion

Front 39

the attraction between molecules that results in the rise of the surface of a liquid when in contact with a solid

Back 39

capillarity

Front 40

mixture in which one or more substances are uniformly distributed in another substance

Back 40

solution

Front 41

substance dissolved in the solvent

Back 41

solute

Front 42

the substance in which the solute is dissolved

Back 42

solvent

Front 43

amount of solute dissolved in a fixed amount of the solution

Back 43

concentration

Front 44

solution in which no more solute can dissolve

Back 44

saturated solution

Front 45

solutions in which water is the solvent

Back 45

aqueous solutions

Front 46

hydroxide ion

Back 46

OH-

Front 47

hydronium ion

Back 47

H3O+

Front 48

solution with a greater number of hydronium ions

Back 48

acid

Front 49

solution that contains more hydroxide ions than hydronium ions

Back 49

base/alkaline

Front 50

scale that compares the relative concentrations of hydronium ions and hydroxide ions in a solution

Back 50

pH scale

Front 51

chemical substances that neutralize small amounts of either an acid or a base added to a solution

Back 51

buffer