chem midterm

Question 1

Different substances evenly mixed ex: sugar water, salt water

Answer 1

Homogenous mixture

Question 2

Different substances not evenly mixed ex: trail mix, cereal

Answer 2

heterogeneous mixture

Question 3

The digits that carry meaning and contribute to its precision

Answer 3

Significant figures.

Question 4

The measure of how much mass is in a given volume

Answer 4

density

Question 5

Amount of matter an object contains

Answer 5

mass

Question 6

spaced occupied by a 3 dimensional shape

Answer 6

volume

Question 7

the average mass of an atom of an element (measured in AMU)

Answer 7

Atomic mass

Question 8

The # of protons in the nucleus of an atom of that element

Answer 8

Atomic number

Question 9

Different forms of an element might have the same number of protons but a different number of neutrons (These variations result in a different atomic mass)

Answer 9

Isotope

Question 10

An atom or group of bonded atoms that has a positive charge (cation) or negative charge (anion)

Answer 10

Ion

Question 11

of protons and neutrons in the nucleus

Answer 11

Mass number

Question 12

The spontaneous emission of radiation from the nucleus of an unstable atom

Answer 12

Radioactivity

Question 13

The time it takes for half of the atoms in a sample to undergo radioactivity decay

Answer 13

half-life

Question 14

The amount of a substance that contains as many particles as there are atoms in exactly 12 g or carbon 12

Answer 14

Mole

Question 15

A form of energy that exhibits wave-like behaviors as it travels through space

Answer 15

electromagnetic radiation

Question 16

The lowest state of an atom

Answer 16

ground state

Question 17

A state in which an atom has a higher potential energy than its ground state

Answer 17

Excited state

Question 18

(lambda) the distance from crest to crest

Answer 18

wavelength

Question 19

(Nu) the number of waves that pass a given point on a specific time– usually one second (waves per second)

Answer 19

frequency

Question 20

A particle of electromagnetic radiation (ER) having no mass and carrying a quantum (fixed amount) of energy

Answer 20

Photon

Question 21

a single packet of matter or energy

Answer 21

quantum

Question 22

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

Answer 22

orbital

Question 23

arrangement of electrons in an atom or ion. Describes how electrons ocupy different sublevels or orbitals.

Answer 23

electron configuration

Question 24

Electrons are arranged in an atom such that each electron occupies the lowest energy orbital available

Answer 24

Aufbau principle

Question 25

Electrons should be placed into separate orbitals before going to the same orbitals

Answer 25

Hund's rule

Question 26

Two arrows cant go on the same orbital

Answer 26

Pauli exclusion

Question 27

Electronegativity increases across a....

Answer 27

period

Question 28

Energy decreases down a...

Answer 28

group

Question 29

negatively charged ion

Answer 29

anion

Question 30

postively charged ion

Answer 30

cation

Question 31

metal

Answer 31

good conductors of heat and electricity

Question 32

the chemical bonding that results from the electrical attraction between laerge number of cations and anions that have been created by the transfer of electrons.

Answer 32

ionic bond

Question 33

properties opposite to metals, made from ions

Answer 33

non-metal

Question 34

substances that conduct electricity when dissolved in water or melted

Answer 34

electrolytes

Question 35

elements that have properties intermediate between metals and non-metals

Answer 35

metalloid (semi-metal)

Question 36

highly reactive, first row of periodic table

Answer 36

alkali metals

Question 37

Alkaline earth metals

Answer 37

second row of the periodic table

Question 38

group 17 of the periodic table, highly reactive and tend to form compouds by gaining electrons from other elements

Answer 38

halogen

Question 39

group 18, low reactivity, full outer electron shell, stable

Answer 39

noble gases

Question 40

one half the distance between the nuclei of identical atoms that are bound together

Answer 40

atomic radius

Question 41

a measure of the ability of an atom in a compound to atraxct the valence elections of another atom in that compound on isolated atoms

Answer 41

electronegativity

Question 42

the energy required to remove one electron from a neutral atom of an element (measured in the gas phase)

Answer 42

ionization energy

Question 43

the electrons occupying the atoms highest energy level (they are always in the S and P orbitals)

Answer 43

Valence electrons

Question 44

Why do certain elements emit radioactivity?

Answer 44

An unfavorable ratio of neutrons to protons can yeild an unstable atom emitting radioactivity (particles/energy) make the atom more stable.

Question 45

What are the forms of radioactive decay?

Answer 45

Alpha, Beta, Gamma

Question 46

what happens when an element emits alpha radiation?

Answer 46

4/2He: subtract 4 from the top number and 2 from the bottom number

Question 47

what happens when an element emits beta radiation?

Answer 47

0/-1e: add 1 to the bottom number

Question 48

Kilo- (King)

Answer 48

1,000

Question 49

Hecto-(henry)

Answer 49

100

Question 50

Deka-(died)

Answer 50

10

Question 51

Deci-(drinking)

Answer 51

1/10

Question 52

centi-(chocolate)

Answer 52

1/100

Question 53

milli-(milk)

Answer 53

1/1000

Question 54

Micro-

Answer 54

1/1000000

Question 55

What happens to an electron in an atom if it aborbs a quantym of energy? What happens when it loses energy?

Answer 55

An electron that abosrbs a quantum of energy will jump to an excited state and when it loses energy it decays and drops down to a ground state.

Question 56

What is a valence electron? How can you determine the # of valence electrons for any given element?

Answer 56

valence electrons are the electrons with the most energy. They are the furthest electrons from the nucelus and are responsible fo rthe characterisitifcs of that element. The number of valence elections for the main block elemernts (those elements in the s + p blocks) is found from the group number: group 1=1, group 2=2, group 13=3, group 14=4, group 15=5, group 16=6, group 17=7 ground 18=8.

Question 57

Which groups of elements are the most reactive?

Answer 57

group 1, the alkali metals and group 17, the halogens