Question

Silicon and phosphorous belongs to same period of the periodic table.

1. State the electronic configuration of silicon and phosphorous.
2. Name the period in which above element occur.

Answer 1

1. The atomic number of silicon (Si) is 14.So its electronic configuration is 2,8,4.
   The atomic number of phosphorous (P) is 15, its electronic configuration is 2,8,5.
2. Silicon and phosphorous belong to the third period as we can see from the electronic configuration these are 3 shells in which electrons are filled so the period of the element is three.