Question

The elements in periods 2 and 3 having stable electronic configuration.​

Answer 1

Answer:

The last elements of these periods have fully filled electronic configurations.

Explanation:

The last elements of period 2 and period 3 are Neon and Argon.

For Neon:  

There are 8 valence electrons in this element and hence, has fully filled electronic configuration and is a stable element.

For Argon:  

There are 8 valence electrons in this element and hence, has fully filled electronic configuration and is a stable element.