The bond order and magnetic property of acetylide ion are same as that of

'A' in the above reaction is:

Given below are two statement: one is labelled as Assertion $$\mathbf{A}$$ and the other is labelled as Reason $$\mathbf{R}$$

Assertion A: $$5 \mathrm{f}$$ electrons can participate in bonding to a far greater extent than $$4 \mathrm{f}$$ electrons

Reason R: $$5 \mathrm{f}$$ orbitals are not as buried as $$4 \mathrm{f}$$ orbitals

In the light of the above statements, choose the correct answer from the options given below

A metal chloride contains $$55.0 \%$$ of chlorine by weight . $$100 \mathrm{~mL}$$ vapours of the metal chloride at STP weigh $$0.57 \mathrm{~g}$$. The molecular formula of the metal chloride is

(Given: Atomic mass of chlorine is $$35.5 \mathrm{u}$$)