3.4 - Quantum Numbers

Question 1

principal quantum number (n)

Answer 1

Describes the size and energy of an atomic orbital.

Whole number values (1,2,3…)

Bohr’s line spectrum is explained by an electron
jumping to a higher energy level (n), and falling
back down to the ground state.

Question 2

secondary quantum number (l)

Answer 2

Describes the shape and energy of an atomic
orbital, with whole number values from 0 to
(n-1) for each value of n.

Question 3

magnetic quantum number (ml)

Answer 3

Describes the orientation of an atomic orbital
in space.

Whole number values between +l to –l,
including zero.

For instance, when l = 1, there are three
possible orbitals: +1,0, and -1.

Question 4

spin quantum number (ms)

Answer 4

FOURTH QUANTUM NUMBER : magnetic
property– when atom is placed in an external
magnetic field, the atom has two
orientations– two opposite spin states.

Two values: +1/2 or -1/2.

Question 5

paul exclusion principle

Answer 5

In a given atom, no two electrons can have
the same set of four quantum numbers (n, l,
ml and ms).

MUST have opposite spins ms.