Question

The density of gold is 19 g/cm³. If 1.9 x 10⁻⁴ g of gold is dispersed in one litre of water to give a sol having spherical gold particles of radius 10 nm, then the number of gold particles per mm³ of the sol will be :
(a) 1.9 x 10¹²
(b) 6.3 x 10¹⁴
(c) 6.3 x 10¹⁰
(d) 2.4 x 10⁶

Answer 1

d) 2.4×10^6.............