Question

The number of atoms in 500 g of a fcc crystal of a metal with density d = 10 g/cm³ and cell edge 100 pm, is equal to ____________.

Options

• 4 × 10²⁵

• 3 × 10²⁵

• 2 × 10²⁶

• 5 × 10²⁴

Answer 1

The number of atoms in 500 g of a fcc crystal of a metal with density d = 10 g/cm³ and cell edge 100 pm, is equal to 2 × 10²⁶.

Explanation:

Number of particles in 'x' g = `"x n"/(ρ"a"^3)`

Number of atoms in 500 g

= `(4 xx 500)/(10 xx (10^-8)^3)`

= 200 × 10²⁴

= 2 × 10²⁶