The longest period in the modern periodic table is

The valency of an element which belongs to 3rd period and 2nd group of periodic table is

The general electron configuration of inert gases

The inert gas element which does not have octet configuration in the outer most orbit is

The element belongs to 3rd period and 17th group is

The element with atomic number 13 belongs to ……………. period and …………….. group.

Where do Na and N belong ?

The atomic numbers of actinide series elements are

Which of the following group elements are known as chalcogens ?

The number of electrons that are present in Cl ion is

Which one of the following has the electronic configuration $1s^{2}2s^{2}2p^{6}1s^2\backslash ,2s^2\backslash ,2p^6$

Potassium and calcium belong to

Which of the following are lanthan ides?

The element with highest electro – negativity belongs to

The general electron configuration of s – block elements are