Xenon crystallises in fcc lattice and the edge length of unit cell is 620 pm. What is the radius of Xe atom?

How many electrons are involved in the reaction, when $$0.40 \mathrm{~F}$$ of electricity is passed through an electrolytic solution?

Which among the following lanthanoids, shows only +3 oxidation state?

Which among the following is used as refrigerants and for air conditioning?