1) Will the amount of hydrogen and helium in the sun increase or decrease over the next few million years? The answer in my book says they will decrease.......but that doesn't make sense to me! The most common type of nuclear fusion in the Sun is hydrogen fusion, so amount of hydrogen will certainly decrease, but shouldn't the amount of helium be INCREASING instead of decreasing? Or will the helium in fact also decrease in amount? 2) Why and how do volcanic eruptions aid in the creation of an atmosphere?