CHEM 1320 Exam 1

Question 1

law of conservation of mass

Answer 1

sum of mass of reactants = sum mass of products

Question 2

law of definite proportions

Answer 2

consistent with all atoms of one element are identical.

Question 3

law of multiple proportions

Answer 3

if you double the proportions you won’t have the same out come as a single proportion

Question 4

dalton’s atomic theory

Answer 4

1) matter is made of tiny indivisible and indestructible atoms.(conservation of mass)
2) atoms of same elements may combine in more than one ration to form 2 or more compounds(multiple proportions)
3) atoms of different elements may combine with each other in a fixed simple whole number ratios to form compounds(definite proportions)
4) all atoms of a given element are identical in mass and properties and different from other elements(incorrect)

Question 5

medeleave

Answer 5

organized the periodic table

Question 6

JJ Thompson

Answer 6

use cathode rays to prove that there are sub-atomic particles. (charge to mass ratio)

Question 7

Miliken

Answer 7

oil drops experiment to show how measure the mass of an electron.

Question 8

Rutherford

Answer 8

gold foil experiment
showed that atoms have small dense nuclei

Question 9

electron

Answer 9

e-, light, negatively charged,

Question 10

proton

Answer 10

p+, massive, pos charged

Question 11

neutron

Answer 11

n, no charge, neutral

Question 12

ions

Answer 12

when the same element has a different number of electrons

Question 13

isotopes

Answer 13

when an atom has a different amount of neutrons

Question 14

allotropes

Answer 14

when and element has different chemical forms (ex. carbon)

Question 15

wavelength

Answer 15

distance between crests
units=nanometers(nm)
decides color

Question 16

amplitude

Answer 16

measurement from line to crest
determine brightness

Question 17

frequency

Answer 17

number of cycles that pass through a stationary point in a given time
units=hertz

Question 18

how wavelength and frequency relate

Answer 18

as wavelength gets bigger frequency gets smaller

Question 19

black body radiation

Answer 19

can tell how hot something is by its light color.

Question 20

planck’s theory

Answer 20

light curves in tiny packets
- more like stairs than a ramp
- Ephoton=hc/λ or hv

Question 21

photoelectric effect

Answer 21

-Albert Einstein
- photon thrown at metal releases e-
- brighter lights will emit more e-

Question 22

Niels bohr

Answer 22

• electrons have only specific orbits and energies
• an electron must be absorbed or evolved to move from one energy level to another

Question 23

absorbed

Answer 23

when an e- goes to a higher energy level because it ha gained energy.

Question 24

emitted

Answer 24

when an e- goes down and energy level because energy is being lost.

Question 25

L. DeBroglie

Answer 25

λ=h/mv
says particle has a wavelength

Question 26

node

Answer 26

where amplitude of wave changes its sign

Question 27

n

Answer 27

• principle quantum number
• intergers (1,2,3,.., “7”)
• size (and energy)

Question 28

ℓ

Answer 28

• angular momentum quantum number
• integers( 0,1,2,3,…(n-1))
• shape of orbital

Question 29

mℓ

Answer 29

-magnetic quantum number
- -ℓ ≤ mℓ ≤ ℓ
- orientation in space (x,y,z)

Question 30

n^2

Answer 30

tells the amount of possible orbitals

Question 31

constructive interference

Answer 31

when 2 waves add together and make a bigger wave

Question 32

destructive interference

Answer 32

when waves cancel each other out

Question 33

diffraction

Answer 33

shows light has both wave nature and particle nature
double slit experiment

Question 34

ms

Answer 34

spin quantum number
(-1/2 or 1/2)

Question 35

s orbital

Answer 35

-spherical shape
-ℓ=0

Question 36

P orbitals

Answer 36

-dumbbell shape
-ℓ=1

Question 37

d orbitals

Answer 37

-clover shape
-ℓ=2
-5 different values for mℓ
-5 different orbitals
-two nodal plaines

Question 38

f orbitals

Answer 38

-ℓ=3
-3 nodal plaines
-10 different values of mℓ
-10 different orbitals

Question 39

Pauli exclusion principle

Answer 39

no two e- can have all 4 quantum number be identical

Question 40

scrounger equation

Answer 40

gives info of the energy and orbitals of e-

Question 41

wave function Ψ

Answer 41

describes wave like nature of the e-

Question 42

Ψ^2

Answer 42

represents an electron orbital

Question 43

solving Schrodinger’s equation for hydrogen gave following info.

Answer 43

-principal quantum number
-angular momentum quantum number
-magnetic quantum number
-spin quantum number.

Question 44

nodes

Answer 44

area where no probability of finding an electron

Question 45

radial nodes

Answer 45

region where the radial wave function is zero.

Question 46

angular nodes

Answer 46

region where angular wave function is zero.