Quantum Number Definitions and Relations

Question 1

What are the 4 Quantum Numbers?

Answer 1

• n
• l
• ml
• ms

Question 2

What does the Quantum Number n represent?

Answer 2

• Principle/primary quantum number
• Represents energy level of electron

*larger n value = electron further from the nucleus

Question 3

What does the Quantum Number l represent?

Answer 3

• Secondary quantum number
• Represents shape of orbital (s, p, d, f)

Question 4

What does the Quantum Number ml represent?

Answer 4

• Tertiary/Third quantum number
• Represents orbital amount per energy level
• Describes specific orbital amongst a set

Question 5

What does the Quantum Number ms represent?

Answer 5

• Represents spin value/direction
• Can only be +1/2 or -1/2
• Identifies one specific electron in an orbital (+ or -)

Question 6

What are possible values of n?

Answer 6

1, 2, 3, …

(it is infinite, but cannot be 0)

Question 7

What are possible values of l?

(determined by n)*

Answer 7

• l = (n-1)
• If n = 3, l may equal 0, 1, or 2 (3 - 1 = 2)

Question 8

What are possible values of ml?

(determined by l)

Answer 8

• ml = -l … l
• If l = 2, ml may equal -2, -1, 0, 1, or 2

Question 9

What are possible values of ms?

(determined by spin direction)

Answer 9

• ms = +1/2 or -1/2
• If first electron is +1/2, the second electron MUST be -1/2