Question

The element whose atomic volume is least is

• A. Thallium
• B. Boron
• C. Aluminum
• D. Gallium

Answer 1

Answer: (B)

In moving from left to right in a period the atomic volume first decreases and then incrases because-

• As we move left to right in a period , one electron and one proton gets added .
• Initially , the increase in nuclear charge overcomes the increase in the no. of electrons. Hence the atomic volume decreases.
• But in the right of the priodic table newly added electrons goes into the p orbital and due to high shielding power of s and p orbitals , atomic volume increase.

Atomic volume of Boron is least