(a) 1 mole of Cu = 63.5 g

(b) Iodine occurs as diatomic molecules

Molecular mass of I₂ = 2 x 126.9 = 253.80 amu

Therefore, mass of 1 mole of l₂ = 253.80 g

(c) 1 mole of K = 39 g

(d) Oxygen occurs as diatomic molecules.

Molecular mass of O₂ = 2 x 16 = 32 amu

Therefore, mass of 1 mole of O₂ = 32 g