(i) Atoms cannot exist independently but molecules can.
(ii) Molecular mass is the sum of masses of the atoms in the molecule whereas, formula unit mass is sum of atomic masses of all atoms in a formula unit of an ionic compound. (NH4)2SO4.
(i) Atoms cannot exist independently but molecules can.
(ii) Molecular mass is the sum of masses of the atoms in the molecule whereas, formula unit mass is sum of atomic masses of all atoms in a formula unit of an ionic compound. (NH4)2SO4.