The vapour density of a chloride of an element is 39.5. The Ew of the elements is 3.82. The atomic weight of the element is ______.

Mw of metal chloride (MClx) = M + x × 35.5                                              = 2 × VD = 2 × 39.5                                             = 79.0Mw = Ew × xValency of metal = xAtomic weight of element = Ew × xMCl3 = 3.82 × x + x × 35.5 = 79x=793.82+35.5≈2Atomic weight = Ew × x = 3.82 × 2 = 7.64.