According to modern ideas about the evolution of stars, on the Sun as a result of thermonuclear reactions, hydrogen turns into helium. How much hydrogen was in the sun before the start of thermonuclear reactions on it?
Now the mass of hydrogen on the Sun is 63% of its total mass. By the beginning of thermonuclear reactions, it consisted of 70% by mass of hydrogen and 30% of helium, which was formed during thermonuclear fusion during the Big Bang.
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