SOLAR SYSTEM

Detailed explanation-1: -By mass, hydrogen and helium combined make up far less than 1% of the Earth, and even if we restrict ourselves to the Earth’s crust, it’s still just a tiny percentage compared to the other, heavier elements. Image credit: Gordon B. Haxel, Sara Boore, and Susan Mayfield from USGS / Wikimedia user michbich.

Detailed explanation-2: -Although hydrogen is the most abundant element in the universe (three times as abundant as helium, the next most widely occurring element), it makes up only about 0.14 percent of Earth’s crust by weight. It occurs, however, in vast quantities as part of the water in oceans, ice packs, rivers, lakes, and the atmosphere.

Detailed explanation-3: -Since the oceans are mostly water, the elements hydrogen and oxygen are the most common.

Detailed explanation-4: -Nine out of every 10 atoms in the universe are hydrogen, the first element and the major constituent of stars. The other 10 percent of all atoms are helium. That’s already 100 percent.