The correct option is
A True
Atomic mass of Hydrogen=
1.007Atomic mass of Oxygen= 15.99
Atomic mass of Nitrogen= 14.006
Atomic mass of chlorine= 35.5
Molecular mass of hydrogen= 2×1.007=2.014
Molecular mass of oxygen= 2×15.99=31.99
Molecular mass of nitrogen= 2×14.006=28.01
Molecular mass of chlorine= 2×35.5=71
This is because in molecular state hydrogen, nitrogen, oxygen and chlorine exist as H2,N2,O2 and Cl2 respectively. Atomic mass is of single atom, while molecular mass of these element is of their combined state and as they exist as diatomic their molecular mass are double of their atomic mass.