Number of atoms of He in 100 amu of He is :

Number of atoms of He in 100 atoms of He (at.mass 4 amu) is

(A) The number of atoms in 52 mole of "He" is 31.3× 10^(24) (B) the number of atoms in 52amu of "He" is 13 (c) The number of atoms in 52g of "He" is 78.26× 10^(23) (D) The number of atoms in 52g of "He" is 52.26× 10^(23)

Calculate Number of nitrogen atoms in 160 amu of NH_(4)NO_(3)