The number of unpaired electrons in 1s² 2s² 2p³ is -

1. 2

2. 0

3. 3

4. 1

Match the following species with their corresponding ground state electronic configuration.

An electronic configuration representing an atom in the excited state is: 

$1.$ $1{\mathrm{s}}^2,2{\mathrm{s}}^{2}2{\mathrm{p}}^1$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$
$2.$ $1{\mathrm{s}}^2,2{\mathrm{s}}^{2}2{\mathrm{p}}^2$
$3.$ $1{\mathrm{s}}^2,2{\mathrm{s}}^{2}2{\mathrm{p}}^2,3{\mathrm{s}}^1$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $$
$4.$ $1{\mathrm{s}}^2,2{\mathrm{s}}^{2}2{\mathrm{p}}^5$

Match the ensuing rules with the corresponding statements:
 

If the electronic structure of oxygen atom is written as $1{\mathrm{s}}^2,<mspace\; width="1em"></mspace>2{\mathrm{s}}^2$  it would violate:

1. Hund's rule.

2. Paulis exclusion principle.

3. Both Hund's and Pauli's principles.

4. None of the above.

The orbital diagram in which both Pauli's exclusion principle and Hund's rule are violated is: 
 

1.
2.
3.
4.

Identify the element with the highest number of unpaired electrons in its ground state from the given options :