Quantum Numbers

Question 1

n

Answer 1

Principal Quantum Number
- distance from nucleus
- higher number = greater potential energy

n = 1,2,3,4…

Question 2

l

Answer 2

Orbital Shape or Angular Momentum Quantum Number
- sub-level (type) of orbital
- orbital shape
- allowed: l = [0,1,2…n-1]

s, p, d, f…
l = 0 (s)
l = 1 (p)…

Question 3

m(l)

Answer 3

Magnetic Quantum Number
- 3D orientation (plane)
- allowed: m(l) = [-l….+l]

p(x), p(y), p(z)
m(l) = 0 (s)
m(l) = -1 (p(x))…

Question 4

m(s)

Answer 4

Magnetic Spin Quantum Number
- maximum 2 electrons with opposite spin
- allowed: m(s) = - or + 1/2

+1/2 (up)
-1/2 (down)

Question 5

Aufbau Principle

Answer 5

Electrons fill the lowest available energy level (as close to the nucleus)

Question 6

Pauli Exclusion Principle

Answer 6

Each orbital holds a max of 2 electrons with opposite spin

Question 7

Hund’s Rule

Answer 7

Electrons do not pair up in an orbital untill all orbitals of the same sub-level are half-filled

Question 8

s1d5

Answer 8

Chromium and molybdenum

Question 9

s1d10

Answer 9

Copper, silver, gold