Question

What is the approximate chemical composition (by mass) with which all stars are born? (the sun is a star)

A) 74% hydrogen, 24% helium, 2% heavier elements
B) 60% hydrogen, 35% helium, 5% heavier elements
C) 80% hydrogen, 15% helium, 5% heavier elements
D) 90% hydrogen, 8% helium, 2% heavier elements

Answer 1

Stars are born with a chemical composition of about 74% hydrogen, 24% helium, and 2% heavier elements. The Sun has a similar composition, indicative of typical stellar make-up.

Step-by-step explanation:

The approximate chemical composition (by mass) with which all stars, including the Sun, are born is approximately 74% hydrogen, 24% helium, and 2% heavier elements. Studies of stellar spectra and the solar atmosphere have shown that hydrogen is the most abundant element, making up about three-quarters of a star's mass, while helium constitutes nearly a quarter. The remaining consists of heavier elements such as oxygen, carbon, neon, iron, nitrogen, silicon, magnesium, and sulfur, which combined make up a smaller percentage of the stellar mass. Therefore, the correct answer to the question is A) 74% hydrogen, 24% helium, 2% heavier elements.