Most of the matter in the universe is thought to be?

Answer 1

The number of protons in the Universe is estimated to be about 1079 or thereabouts. A very large number. The existence of electrons and neutrons does not alter this number very much. This was worked out in the 1930s by Arthur Eddington, from fundamental principles though recent ideas may have altered this number slightly, and the basis for it.

Recent work on effects abroad in the Universe are firming up to support the idea that there are a couple of other sources, yet to be identified with certainty, called Dark Matter, and Dark Energy.

Taking reasonable estimates for these, current numbers are that Ordinary Matter is about 4.6% of the material, Dark Matter another 23%, and Dark Energy about 72%. The Dark components are made of sub-atomic particles of which our present knowledge is very uncertain.

These outnumber Ordinary matter by some 20 to 1, but that only adds another 1 or so to the exponent of the Eddington Number of 1080.

Answer 2

Hydrogen gas. When the universe formed, 3/4 of it was hydrogen and 1/4 was helium with trace amounts of lithium and a smidgen of beryllium.

MOST of the hydrogen remains in the form of vast interstellar clouds of the gas. Only a tiny fraction of it has collapsed into the form of stars--a few percent.

Then again, most of the mass of the universe is some material we cannot see. It is not directly visible to us, but we can see its effects, which is how we know it is there.

Answer 3

Most of the matter in the universe is what is known as dark matter; its actual composition is not known, but it has been observed indirectly because of its gravitational effects. Most of the matter that we can see is made of hydrogen.

Answer 4

Atoms. Yes but hydrogen is the element most abundant.

Answer 5

Empty space - nothing- a vacuum.