Question

The most abundant element in universe is:
A.Helium
B.Oxygen
C.Silicon
D.Hydrogen

Answer 1

Hint: It is the first element in the periodic table. And it is the only element with no neutrons.

Complete step by step answer:
We should know that hydrogen is more plentiful than any other element. It is making up about 3/4th the mass of the universe. It is found in vast quantities in dust clouds between stars.
Helium is second, making up almost all of the remaining 25%. Oxygen is the third most abundant element of the universe. On earth, oxygen is the most common element making up about 47% of earth’s mass.
So, our correct answer is option D, Hydrogen.

Additional information
Hydrogen is present in the universe in the form of molecular hydrogen. We should know that molecular hydrogen is formed when two hydrogen atoms react together to form a mutual bond. It is also the smallest, lightest, and arguably the most important molecule, essential for the formation of stars and planets, and for life itself. Hydrogen is found almost everywhere in the universe. It occurs between and within stars, and in the enormous gas and dust clouds that exist throughout interstellar space.
Hydrogen is the most important molecule in space, as well as the most abundant. If we are to understand all the processes involved in how matter is formed in space, we need to start there.
As hydrogen is only with just one proton and one electron (it's the only element without a neutron) — is the simplest element in the universe, which explains why it's also the most abundant.

Note: we should not get confused between abundant elements on earth and abundant elements in the universe. Oxygen and after that silica are the most abundant element on earth. Whereas hydrogen is abundant in the universe. Helium comes in second place after hydrogen in abundance in the universe. So, we should not get confused between hydrogen and helium.