•an element whose third shell contains two p electrons

The element whose third shell contains two p electrons is, silicon.

Explanation:

Electronic configuration : It is defined as the representation of electrons around the nucleus of an atom.

Number of electrons in an atom are determined by the electronic configuration.

Atomic number : It is defined as the number of electrons or number of protons present in a neutral atom.

As per question the electronic configuration will be,

The total number of electrons = [2 + 2 + 6 + 2 + 2] = 14

The atom having atomic number 14 is silicon.

Hence, the element whose third shell contains two p electrons is silicon.