Question

An element A (Atomic weight = 100) having bcc structure has a unit cell edge length 400 pm. The number of atoms in 10 g of A is ______ × 10²² unit cells.

Options

• 2.066

• 0.025

• 3.011

• 5.023

Answer 1

An element A (Atomic weight = 100) having bcc structure has a unit cell edge length 400 pm. The number of atoms in 10 g of A is 3.011 × 10²² unit cells.

Explanation:

a = 400 pm

d = `((2)(100))/((6.023 xx 10^23)(400 xx 10^-10)^3)`

= 5.188 g/cm³

10 g of A → 6.023 × 10²² atoms

→ 3.011 × 10²² unit cells