exam 2: ch.3 and 4

Question 1

theory of electromagnetic radiation

Answer 1

• James maxwell
• radiation travels through space as waves
  -travels at the speed of light

Question 2

wavelength (y)

Answer 2

distance between one wave crest to another

equation used to find wavelength
y = c/v

Question 3

frequency (v)

Answer 3

the number of crests that pass through a stationary point in space per second.

cycles per second (s^-1)
Hertz = 1Hz =1 s^-1

equation to find frequency
v = c/y

Question 4

amplitude

Answer 4

how big the crescent is
doesn’t affect wavelength or frequency

Question 5

frequency and wavelength have a inverse relationship

Answer 5

short wavelength = highest energy
longest wavelength = lowest energy

equation:
c=yv
where
c- speed of light; constant (2.998 x10^8 m/s)
y- wavelength
v- frequency

Question 6

blackbody radiation

Answer 6

the electromagnetic radiation emited by a perfect blackbody at a given temperature

Max plank

Question 7

wiens displacement law

Answer 7

Ymax x T = constant

Question 8

energy of one photon

Answer 8

E= hc/y
E unit is in jules

E= energy
h= planks constant ; j/s
c= 2.98 x 10^14 m/s
y= wavelength m

Question 9

photoelectric effect

Answer 9

electrons can be ejected from a metal surface when light having a frequency greater than some threshold frequency is shone on it.

photoelectrons are emitted when the frequency of radiation exceeds some minimum threshold frequency.

greater the frequency, the greater kinetic energy imparted to the escaping electrons.

Question 10

key observations of photoelectric effect

Answer 10

number of electrons increase as brightness increased.

the kinetic energy does NOT depend on brightness.

kinetic energy increased with increasing frequency of light.

Question 11

work function

Answer 11

the minimum energy required to release an electron from the surface of a metal.

planks constant x threshold frequency (Eo=cV)

Question 12

Balmer equation

Answer 12

accurate for hydrogen gas

y= 364.56 nm (m^2/ m^2-4)

Question 13

Rydberg equation

Answer 13

accurate for other gases besides hydrogen.
directly proportional to wave energy!

1/y = Rh (1/n1^2) - (1/n2^2)

Rh= ryberg constant; 1.0974 x10^7 m-1

Question 14

energy level

Answer 14

excited state (up) - short term state. not as happy

ground state (down) - most stable state. electron is happy

when electron comes down it emits energy.

Question 15

change in energy

Answer 15

change in energy = (-2.18 x 10^-18 J ) ( 1/nf^2 - 1/ni^2)

nf = final
ni = inital

Question 16

small waves have _______.

Answer 16

big energy

Question 17

big waves have ________.

Answer 17

small energy

Question 18

as frequency increases it’ s ______ increases.

Answer 18

kinetic energy

Question 19

absorption

Answer 19

INCREASE
n=1 , n=3
n=3 , n=5

Question 20

emission

Answer 20

DECREASE
n=2 , n=1
n=3 , n=2

Question 21

visable light

Answer 21

wavelength of 380 - 700 nm

Question 22

bohr’s model

Question 23

Louis de broglie

Question 24

n

Answer 24

principle quantum number

Defines the location of E level.
n value defines the energy of an e- in the orbital

can NOT be zero
ex: 1,2,3,4

Question 25

l

Answer 25

angular momentum quantum number

defines the shape of a orbital

0 = s orbital
1= p orbital
2= d orbital
3= f orbital

Question 26

m1

Answer 26

magnetic quantum number

Question 27

ms

Answer 27

spin quantum number