Unit 2 - Quantum Theory

Question 1

What equation describes the relationship between wavelength and frequency?

Answer 1

λ = c/v

c = speed of light
v = frequency

Question 2

What is the relationship between frequency and energy?

Answer 2

E = hv

h = planck’s constant
v = frequency

Question 3

What is the relationship between wavelength and energy?

Answer 3

E = hc / λ

h = planck’s constant
c = speed of light

Question 4

What is the formula for kinetic energy?

Answer 4

KE = Enegry of photon - Work

Question 5

What is the formula for thershold wavelength?

Answer 5

thershold λ = hc / W

h = plank’s constant
c = speed of light
w = work

Question 6

What are the values of quantum number l?

Answer 6

• s = 0
• p = 1
• d = 2
• f = 3

Question 7

How can you calculate number of angular nodes?

Answer 7

number of angular nodes = l

Question 8

How can you calculate number of radial nodes?

Answer 8

number of radial nodes = n - l - 1

Question 9

What plane is the angular node of 2px located?

Answer 9

xz plane

Question 10

What plane is the angular node of 2py located?

Answer 10

xz plane

Question 11

What plane is the angular node of 2pz located?

Answer 11

xy plane

Question 12

What does a superscript on the axis subscript indicate?

ex: 3dz^2

Answer 12

It indicates that the electron density is along the specified axis.

Question 12

What does a superscript on the axis subscript indicate?

ex: 3dz^2

Answer 12

It indicates that the electron density is along the specified axis.

Question 13

What are the features of radial factors?
R(r) x r

Answer 13

• represents wave function
• number of times graph crosses x-axis = number of radial nodes
• when l = 0 (s), there is a maximum at r = 0
• when l = 1-3 (p,d,f), there is a zero at r = 0

Question 14

What are the features of radial electron densities?
R(r)^2 x r

Answer 14

• represents probablility of electron density
• maxima decreases as r increases
• when l = 0 (s), maximum at r = 0
• when l = 1,2,3 (p,d,f), zero at r=0

Question 15

What are the features of radial distribution plots?
r^2 R^2 x r

Answer 15

• represents average distance between nucleus and electrons
• maxima increases as r increases
• number of maximum = n - l
• all plots start at 0,0
• maximum = most probable distance, increases as n increases, decreases as l increases

Question 16

What is the relationsip between wavelength and mass?

Answer 16

Inverse: larger mass, shorter wavelength; smaller mass, longer wavelength

Question 17

How do you convert between nm and m?

Answer 17

• m to nm: multiply by 10^9
• nm to m: multiply by 10^-9

Question 18

How do you convert beteween J and kJ?

Answer 18

• kJ to J: multiply by 10^3
• J to kJ: multiple by 10^-3

Question 19

What was de Broglie’s hypothesis?

Answer 19

• electrons can have wave-particle duality
• de Broglie wavelength = h/mv

Question 19

If an electron moves from n=4 to n=2 is energy emitted or absorbed?

Answer 19

emitted, positive E

Question 20

If an electron moves from n=2 to n=4 is energy emitted or absorbed/

Answer 20

absorbed, negative E

Question 21

What is the relationship between energy and wavelength?

Answer 21

Inverse