Give the chemical symbol of an element in the third period (row) of the periodic table with four 3p electrons.

The chemical symbol of the element is Sulfur.

Explanation:

The element which is present in third period of the periodic table having four 3p electrons is Sulfur. Sulfur is the 16th element of the periodic table which has 6 valance electrons.

The electronic configuration of this element is:  

This element is considered as a non-metal because it will accept electrons in order to attain stable electronic configuration.

Hence, the chemical symbol of the element is Sulfur.