Explain why the electronegativity of Ga, In and Tl will not vary very much.

Explain why the EN's of Ga, In and TI do not vary much though they are expected to decrease in the group.

Explain why the planets do not twinkle.

In which block of the periodic table the electronegativities of the elements are very similar ?

Explain why DeltaABC ~= DeltaFED .

Explain why inspite of nearly the same electronegativity, oxygen forms hydrogen bonding while chlorine does not.

Explain why atomic radius of Ga is less than that of Al.

Explain why the following systems are not aromatic?

Explain how the radii of the alkali metals vary in the group? Are they obeying the periodic law.