Question

Part A

Classify each orbital diagram for ground-state electron configurations by the rule or principle it violates.

Drag the appropriate items to their respective bins.

Answer 1

Concepts and reason

This problem is based on three basic rules of filling of electrons in the atomic shells and subshells. Their rules are Aufbau rule, Hund's rule, and Pauli's exclusion principle.

Fundamentals

Aufbau rule: It states that the subshells are arranged in increasing order of their \(\mathrm{n}+\mid\) value where \(\mathrm{n}\) is the number of main shell and \(l\) is the number of subshell. Hund's rule: Pairing of electrons in subshells of same energy starts only after each subshell is occupied by at least one electron.

Pauli's exclusion principle: Any two electrons present in an atom cannot have the same set of all the four quantum numbers.

 

The following orbital diagrams violate Aufbau rule.

In first diagram, n + l value of 3p is 3 + 1 = 4

Whereas n + l value of 3s is 3 + 0 = 3

So, 3s should be filled first not 3p

In second diagram, n + l value of 3d is 3 + 2 = 5

n + l value of 4p is 4 + 2 = 6

n + l value of 4s is 4 + 0 = 4

so filling order should be 4s<3d<4p

 

The following orbital diagrams violate Hund’s rule.

In the first diagram, there is the pairing of electrons while orbitals are still empty.

In the second diagram, singly present electrons are of opposite spins which is against Hund’s rule.

 

The following orbital diagrams violate Pauli’s rule.

The first two electrons in \(2 p\) orbital have same set all four quantum numbers that is \(n=2,1=1, m_{l}=-1, s=\) \(m_{s}=+\frac{1}{2}\) Which is in violation to Pauli's exclusion principle.