Which from following reactions is not possible for benzene due to reversible nature?

Calculate the volume of unit cell when metal having density $1 \mathrm{~g} \mathrm{~cm}^{-3}$ and molar mass $23 \mathrm{~g} \mathrm{~mol}^{-1}$ crystallises to form bec structure.

Which polymer is obtained from monomers using

Which from following elements belongs to the actinoids?