Bio 1080 Chapter 2

Front 1

matter

Back 1

anything that contains mass and

occupies space

Front 2

states of matter

Back 2

solid, liquid, and gas

Front 3

element

Back 3

a substance that cannot be

broken down to other substances by chemical

reactions

Front 4

element examples

Back 4

H, C, N, O, P, Ag, Au

Front 5

compounds

Back 5

made of 2 or more elements in a fixed ratio CO2, H2O, NH3- a compound has characteristics different from those of its elements

Front 6

Carbon, hydrogen, oxygen, and nitrogen

Back 6

make up 96 % > of all living matter

Front 7

trace elements

Back 7

are those required by an organism in minute quantities

Front 8

atom

Back 8

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

Front 9

atoms are composed of

Back 9

protons, neutrons, and electrons

Front 10

protons

Back 10

positively charged particles

Front 11

neutrons

Back 11

neutral particles

Front 12

electrons

Back 12

negatively charged particles

Front 13

nucleus

Back 13

center of the atom, where protons and neutrons are located

Front 14

orbitals

Back 14

three-dimensional space surrounding the nucleus where electrons are found 90% of the time

Front 15

atomic number

Back 15

number of protons in the nucleus of an atom, also the number of electrons in a neutral atom

Front 16

mass number

Back 16

an element’s mass number is the sum of

protons plus neutrons in the nucleus

Front 17

an element's mass # is located

Back 17

directly underneath it on the table of elements

Front 18

an element's mass # is located

Back 18

in the upper left hand corner of it's position on the table of elements

Front 19

calculation for neutrons

Back 19

atomic mass- atomic number

Front 20

isotopes

Back 20

Atoms of the same element that possess

different numbers of neutrons

Front 21

isotopes have

Back 21

same atomic number, different mass numbers

Front 22

radioactive isotopes

Back 22

decay spontaneously, giving off particles and

energy

Front 23

stable isotopes of carbon and nitrogen are

Back 23

useful in biology, particularly in food web studies

Front 24

electrons have more energy

Back 24

the farther from the nucleus they are

Front 25

valence electrons

Back 25

electrons in the outermost shell, or valence shell

Front 26

orbitals contain ____ electrons

Back 26

two

Front 27

orbitals vs energy shells

Back 27

orbitals (location): each hold 2 electrons- energy shells (indicates energy level): 1st holds 2, the rest hold 8

Front 28

octet rule

Back 28

atoms tend to establish completely full outer energy levels

Front 29

the period table

Back 29

arranges all elements according to their atomic number and number of valence electrons

Front 30

chemical bonds

Back 30

created when atoms with incomplete valence shells share or transfer valence electrons with

certain other atoms, usually resulting in the atoms staying close together

Front 31

covalent bond

Back 31

the sharing of a pair of valence electrons by two atoms (ex. O2)

Front 32

molecule

Back 32

consists of two or more atoms held together by covalent bonds

Front 33

single bond

Back 33

the sharing of one pair of valence electrons

Front 34

double bond

Back 34

the sharing of two pairs of valence electrons

Front 35

electronegativity

Back 35

an atom’s attraction for the electrons in a covalent bond

Front 36

non-polar covalent bonds=

Back 36

equal sharing of electrons

Front 37

polar covalent bonds=

Back 37

unequal sharing of electrons (ex. H20)

Front 38

partial charge

Back 38

caused by the unequal sharing of electrons in polar covalent bonds

Front 39

the more electronegative an atom

Back 39

the more strongly the atom pulls shared electrons toward itself

Front 40

electronegativity of O

Back 40

3.5

Front 41

electronegativity of N

Back 41

3.0

Front 42

electronegativity of C

Back 42

2.5

Front 43

electronegativity of H

Back 43

2.1

Front 44

ion

Back 44

atoms that have gained or lost electrons, and are therefore charged particles

Front 45

cation

Back 45

more protons than electrons = net positive charge

Front 46

anion

Back 46

fewer protons than electrons = net negative charge

Front 47

ionic bonds

Back 47

Formed by the attraction of oppositely charged ions

Front 48

ionic bonds form

Back 48

a crystal lattice because of the oppositely charged ions attracting each other

Front 49

hydrogen bond

Back 49

forms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom

Front 50

hydrogen bonds in living cells

Back 50

usually oxygen or nitrogen atoms

Front 51

chemical reactions

Back 51

involve the making and breaking of chemical bonds

Front 52

reactants

Back 52

the starting molecules of a chemical reaction

Front 53

products

Back 53

the final molecules of a chemical reaction

Front 54

photosynthesis

Back 54

6H2O + 6CO2 --------> C6H12O6 + 6O2

Front 55

chemical equilibrium

Back 55

reached when the forward and reverse reaction rates are equal

Front 56

radioactive isotope

Back 56

one in which the nucleus decays spontaneously, giving off particles and energy