Unit 1: Chemistry of Life

Question 1

matter

Answer 1

anything that takes up space & has mass

Question 2

element

Answer 2

a substance that cannot be broken down to other substances by chemical reactions

Question 3

compound

Answer 3

a substance containing of 2 or more different elements combined in a fixed ratio

Question 4

essential elements

Answer 4

elements that an organism needs to live a healthy life & reproduce

Question 5

trace elements

Answer 5

an element indispensable for life but required in extremely minute amounts

Question 6

atom

Answer 6

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

Question 7

neutron

Answer 7

a subatomic particle having no electrical charge

Question 8

electron

Answer 8

a subatomic particle having a single negative electrical charge

Question 9

proton

Answer 9

a subatomic particle having a single positive electrical charge

Question 10

nucleus

Answer 10

the center of an atom

Question 11

dalton

Answer 11

a unit used to measure the size of atoms and subatomic particles
(same as amu: atomic mass unit)

Question 12

atomic number

Answer 12

number of protons of an element

Question 13

mass number

Answer 13

sum of protons + neutrons

Question 14

atomic mass

Answer 14

total mass of an atom

Question 15

isotopes

Answer 15

different forms of the same element

Question 16

radioactive isotope

Answer 16

an unstable isotope in which the nucleus decays spontaneously, giving off particles of energy

Question 17

energy

Answer 17

the capacity to cause change, esp. by doing work

Question 18

potential energy

Answer 18

the energy that matter possesses bc of its location or structure

Question 19

electron shells

Answer 19

an energy level of electrons at a characteristic avg distance from the nucleus of an atom

Question 20

valence electrons

Answer 20

electrons on the outermost electron shell

Question 21

valence shell

Answer 21

the outermost electron shell

Question 22

chemical bonds

Answer 22

An attraction btwn 2 atoms, resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms.
The bonded atoms gain complete valence shells.

Question 23

molecule

Answer 23

2 or more atoms held together by covalent bonds

Question 24

single bond

Answer 24

a pair of shared valence electrons

Question 25

double bond

Answer 25

the sharing of 2 pairs of valence electrons

Question 26

valence

Answer 26

the bonding capacity of an atom; usually equals # of electrons required to complete valence shell

Question 27

electronegativity

Answer 27

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

Question 28

nonpolar covalent bond

Answer 28

electrons are shared equally bc the two atoms have similar electronegativity

Question 29

polar covalent bond

Answer 29

electrons are not shared equally bc one atom is more electronegative than another

Question 30

ion

Answer 30

an atom that has gained or lost one or more electrons, thus acquiring a charge; when 2 atoms are so unequal, one strips the other of a valence electron

Question 31

cation

Answer 31

positively charged ion

Question 32

anion

Answer 32

negatively charged ion

Question 33

ionic bond

Answer 33

an attraction btwn cations & anions bc of their opposite charges

Question 34

ionic compounds

Answer 34

(or salts) compounds formed by ionic bonds

Question 35

hydrogen bond

Answer 35

the con-covalent attraction btwn a hydrogen & an electronegative atom

Question 36

van der Waals interactions

Answer 36

weak attractions btwn molecules that only occur when atoms & molecules are very close

Question 37

reactants

Question 38

products

Question 39

chemical equilibrium

Question 40

polar molecule

Question 41

cohesion

Question 42

adhesion

Question 43

surface tension

Question 44

kinetic energy

Question 45

thermal energy

Question 46

temperature

Question 47

heat

Question 48

calorie (cal)

Question 49

kilocalorie (kcal)

Question 50

specific heat

Question 51

heat of vaporization

Question 52

evaporative cooling

Question 53

solution

Question 54

solvent

Question 55

solute

Question 56

aqueous solution

Question 57

hydration shell

Question 58

hydrophilic

Question 59

hydrophobic

Question 60

molecular mass

Question 61

mole

Question 62

molarity

Question 63

hydrogen ion

Question 64

hydroxide ion

Question 65

hydronium ion

Question 66

acid

Question 67

base

Question 68

pH

Question 69

buffer

Question 70

ocean acidification