Question

How many atomes of helium (He) are present in 100 amu of helium .

Answer 1

1 mole of He atom = 4.003 amu = 6.023 X 10²³ atoms

Therefore 1 amu of He atom = (6.023 X 10²³ / 4) atoms

So 100 amu of He atom will have = (6.023 X 10²³ X 100 / 4) atoms

= 1.506 X 10²⁵ atoms.