If we assume the Sun is made totally out of hydrogen, how many hydrogen atoms are contained with the Sun? If the Sun converts half of these hydrogen atoms into helium over its lifetime of about ten billion years, how many hydrogen atoms are converted per second?

Question

Mass of Sun = 1.989 x 10 to the 30 kg
Mass of Mh = 1.6735 x 10 to the -27 kg

Answer 1

Compute the number of moles of H atoms (or ions) by dividing the mass of the sun by 1.008 g/mole. Then multiply that by Avogadro's number, 6.02*10^23 particles/mole

(Hydrogen is not molecular or neutral atoms in the sun; it is ionized.)

Take half the number of H atoms and divide it by 10^9 years, converted to seconds, to answer the second question.