chapter 2

Question 1

matter

Answer 1

anything that occupies space and has mass

Question 2

element

Answer 2

a substance that cannot be broke down to other substances

Question 3

compound

Answer 3

a substance containing two or more elements in a fixed ration

Question 4

trace element

Answer 4

an element that is essential for life but required in extremely minute amounts

Question 5

atom

Answer 5

the smallest unit of matter that retains the properties of an element

Question 6

proton

Answer 6

positive charge, found in nucleus

Question 7

neutron

Answer 7

neutral charge, found in nucleus

Question 8

electron

Answer 8

negative charge, orbit the nucleus

Question 9

nucleus

Answer 9

an atoms central core, contains genetic material in the form of chromosomes

Question 10

atomic number

Answer 10

number of protons in each atom of a particular element

Question 11

mass number

Answer 11

sum of the number of protons and neutrons in the atoms nucleus

Question 12

atomic mass

Answer 12

total mass of atom, atomic weight, whole number, the atomic mass approximately equals the mass number

Question 13

isotopes

Answer 13

atomic form of an element each with the same number of protons but a different number of neutrons

Question 14

radioactive isotopes

Answer 14

an isotope whose nucleus decays spontaneously giving off particles and energy

Question 15

electron shells

Answer 15

a level of electrons at a characteristic average distance form the nucleus

Question 16

ionic bond

Answer 16

a chemical bond resulting from the attraction between oppositely charged ions

Question 17

covalent bonds

Answer 17

a type of strong chemical bond in which two atoms share one or more pairs of valence electrons

Question 18

chemical bonds

Answer 18

an attraction between two atoms resulting from a sharing of outer-shell electrons or the presence of opposite charges in the atoms. the bonded atoms gain complete outer electron shells

Question 19

molecule

Answer 19

two or more atoms held together by covalent bonds

Question 20

electronegativity

Answer 20

the attraction of a given atom for the electrons of a covalent bond

Question 21

non polar covalent bonds

Answer 21

electrons are shared equally between two atoms of similar electronegativity

Question 22

polar covalent bonds

Answer 22

differ in electronegativity. the shared electrons are pulled closer to the more electronegative atom, making it slightly negative and another slightly positive (water)

Question 23

salt

Answer 23

a compound resulting from the formation of an ionic bond

Question 24

hydrogen bond

Answer 24

a weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bind in another molecule

Question 25

polar molecule

Answer 25

a molecule containing polar covalent bonds and having an unequal distribution of charged in different regions of the molecule

Question 26

chemical reaction

Answer 26

the making and breaking of chemical bonds, leading to changes in the composition of matter

Question 27

reactant

Answer 27

a starting material in a chemical reaction

Question 28

product

Answer 28

an ending material in a chemical reaction

Question 29

cohesion

Answer 29

the sticking together of molecules of the same kind of often by Hydrogen bonds

Question 30

adhesion

Answer 30

the attraction between different kinds of molecules

Question 31

surface tension

Answer 31

a measure of how difficult it is to starch or break the surface of a liquid

Question 32

thermal energy

Answer 32

kinetic energy due to the random motion of atoms and molecules, energy in its most random form

Question 33

temperature

Answer 33

a measure in degrees of the average thermal energy of atoms and molecules in the body of matter

Question 34

heat

Answer 34

thermal energy in transfer from one body of matter to another

Question 35

evaporative cooling

Answer 35

the process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest energy changing from the liquid to gaseous state

Question 36

solution

Answer 36

a liquid that is a homogeneous mixture of two or more substances

Question 37

solvent

Answer 37

the dissolving agent in a solution

Question 38

solute

Answer 38

a substance that is dissolved in a solution

Question 39

aqueous solution

Answer 39

a solution in which water is the solvent

Question 40

acid

Answer 40

a substance that increases the hydrogen ion concentration in a solution

Question 41

base

Answer 41

a substance that decreases the hydrogen ion concentration in a solution

Question 42

pH scale

Answer 42

a measure of the acidity or a solution, ranging from most acidic to most basic

Question 43

buffer

Answer 43

a chemical substance that minimizes changes in pH by accepting hydrogen ions from or donating them to solutions

Question 44

ocean acidification

Answer 44

processed by which the pH of the ocean is lowered (made more acidic) when excess atmospheric CO2 dissolved in seawater