Chapter 2

Question 1

define matter

Answer 1

anything that occupies space and has mass

Question 2

define mass

Answer 2

the quantity of matter an object has

Question 3

define elements

Answer 3

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

Question 4

define atom

Answer 4

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

Question 5

define nucleus

Answer 5

makes up the bulk of the mass of the atom and consists of two kinds of subatomic particles, a proton and neutron.

Question 6

define atomic number

Answer 6

the number of protons in an atom

Question 7

define mass number

Answer 7

the total number of protons and neutrons of the atom

Question 8

define electrons

Answer 8

negatively charged particles that balances the amount of protons

Question 9

define orbital

Answer 9

a three-dimensional region around a nucleus that indicates the probable location of an electron

Question 10

define isotopes

Answer 10

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

Question 11

define compounds

Answer 11

atoms of two or more elements in fixed proportions

Question 12

define chemical bonds

Answer 12

the attractive forces that hold atoms together

Question 13

define covalent bond

Answer 13

a covalent bond forms when two atoms share one or more pairs of electrons

Question 14

define molecule

Answer 14

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

Question 15

define ion

Answer 15

an atom or molecule with an electrical charge

Question 16

define ionic bond

Answer 16

positive and attractive bond

Question 17

states of matter: solid

Answer 17

atoms or molecules are more closely linked together than of a gas or liquid, moves less rapidly, maintains a fixed volume and shape

Question 18

define chemical reaction

Answer 18

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

Question 19

define metabolism

Answer 19

all of the chemical reactions that occur in an organism

Question 20

define activation energy

Answer 20

the amount of energy needed to start a reaction

Question 21

define catalyst

Answer 21

reduce the amount of activation energy needed for a reaction to take place

Question 22

define enzyme

Answer 22

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

Question 23

define redox reactions

Answer 23

reactions in which electrons are transferred between atoms. a reactant gains one or more electrons

Question 24

define polar bond

Answer 24

uneven distribution of charge

Question 25

define hydrogen bond

Answer 25

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

Question 26

define cohesion

Answer 26

an attractive force that holds molecules of a single substance together

Question 27

define adhesion

Answer 27

the attractive force between two particles of different substance, such as water molecules and glass molucules

Question 28

define capillary

Answer 28

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

Question 29

states of matter: ice

Answer 29

open spaces, low density

Question 30

define solution

Answer 30

a mixture in which one or more substances are uniformly distributed in another subtance

Question 31

define solute

Answer 31

a substance dissolved in the solvent

Question 32

when solvent

Answer 32

the substance in which tge sikute is dissolved

Question 33

define concentration

Answer 33

the amount of solute dissolved in a fixed amount of this solution

Question 34

define saturated solution

Answer 34

one in which no more solute can dissolve

Question 35

define aqueous solution

Answer 35

solutions in which water is the solvent

Question 36

define acid

Answer 36

number of hydronium ions in a solution is greater than the number of hydroxide ions

Question 37

define base

Answer 37

the solution contains more hydroxide ions than hydronium ions

Question 38

define buffers

Answer 38

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