Question

What principles or rules are violated in the following electronic configuration \\(1s^{2}2s^{3}\\)?

Aufbau’s principle
Hund’s principle
Pauli’s exclusive principle
Mendeleev’s rule

Answer 1

Answer:

Pauli's exclusion principle is violated here.

Explanation:

Pauli's exclusion principle states that no two electrons in an atom can have the same values of all four quantum numbers.

Now lets discuss about the given electronic configuration in the question

i.e.  $1s^{2} 2s^{3}$ .

In this configuration three electrons are present in 2s orbital. So if we check the values of various quantum numbers we see the following results for the electrons of 2s orbital

for 1st electron in 2s orbital  n=1, l=0 , m=0, s= +1/2

for 2nd electron in 2s orbital n=1, l=0, m=0, s=-1/2

for 3rd electron in 2s orbital  n=1, l=0, m=0, s=+1/2

So , as we can see that in the first and third electrons the values of all four quantum numbers are same it violates the Pauli's exclusion principle.