Mass of #1# mole of #Cr# is #51.996 g.#
Mass of #1.002 mol# of #Cr# is;
#= 51.996gcancel(mol^-1) xx 1.002cancel(mol)#
#= 52.099 g#
Similarly,
Mass of #1# mole of #Ne# is #20.179 g.#
Mass of #4.08 xx 10^-8 mol# of #Ne# is;
#= 20.179gcancel(mol^-1) xx 4.08 xx 10^-8cancel(mol)#
#= 8.233 xx 10^-7 g#