LT#2: Quantum Numbers, Orbital Diagrams and Electron Configurations

Question 1

What does the quantum number “n” describe?

Answer 1

Orbital size and energy level

The higher the value of n, the larger the orbital and the more energy electrons have

Question 2

What does the quantum number “l” describe?

Answer 2

The shape of the orbital. When l equals

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

Question 3

How are the possible values of “l” calculated?

Answer 3

Positive integers that ranges in value from 0 to (n-1)

Question 4

What does the quantum number “ml” describe?

Answer 4

The orientation or plane of the orbital

Number of ml values indicates how many orbitals of the same shape there are

Question 5

How are the possible values of “ml” calculated?

Answer 5

Integers that range from –l to +l.

Question 6

What does the quantum number “ms” describe?

Answer 6

2 electrons in the same orbital spin opposite directions to balance their repulsive forces.

ms describes the direction a particular electron is spinning

Question 7

What are the possible values of “ms”?

Answer 7

can only equal +½ and -½

By convention we use +½ for the first electron in the orbital.

Question 8

Describe the Pauli Exclusion Principle

Answer 8

Becuase of the ms value, no 2 electrons in an atom have the same set of quantum numbers

Question 9

What is the order of orbitals from lowest to highest energy (up to 4p)?

Answer 9

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p

Question 10

Describe the Aufbau Principle?

Answer 10

Arranged by atomic number an elements set of quantum numbers is exactly the same as the last one with one more electron tacked on in the lowest possible energy level.

Question 11

What is Hund’s Rule

Answer 11

When drawing orbital diagrams each orbital with the same amount of energy receives one electron before pairing and when electrons are added singly to orbitals, they must have the same spin (+½).