Write the formulas of methane . Also name the elements presents in them.

Explanation

The general electronic configuration of lathanoids is `(n-2)f^(1-14) (n-1)^(0-1) ns^2`. As such lanthanoid have almost Identical configurations for the outermost two shells and differs only in the number of 4f electrons. Since these 4f electrons are very effectively shielded from interaction with other elements by overlapping 6s and 5d electrons and hence show very little difference in their chemical reactivity.