The Sun is composed of ________ % hydrogen, ________ % helium and ________ % other elements, respectively.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 74, 23.5 and 2.5
The Sun is a ball of hot gas made almost entirely of the two lightest elements. By mass, about three-quarters is hydrogen and nearly one-quarter is helium; all the heavier elements together (oxygen, carbon, neon, iron and others) make up only about 2 to 2.5%. These figures fit 74%, 23.5% and 2.5%.
In the Sun’s core, hydrogen is slowly turned into helium by nuclear fusion, which is the source of its energy.