How many atoms are there in the sun if all the atoms are hydrogen and if the mass of the sun is 2 x 10 to the power of 30 kg and the mass of a hydrogen atom is 1.67 x 10 to the power of -27 kg?

Answer 1

Mass of 1 hydrogen atom = 1.67 × 10−27 kg

Mass of sun = 2 x 1030 kg

So the ratio of the mass of the sun to that of a H atom

= (2 x 1030) / (1.67 × 10−27)

= (2 / 1.67) x (1030 / 10−27)

= 1.2 x 1057

If the sun were entirely composed of H atoms, this would be the number of H atoms in the sun.