In terms of mass, how much of the universe is made up of atoms?

Question

Let's see what most people think about this.....

Answer 1

It depends on your view of dark matter. Dark matter is about 85% of the universe's total matter. If dark matter consists of massive compact halo objects (MACHOs), then it is atomic matter, and almost all of the universe's mass would be atomic, excepting the possibility of quark matter, which might exist in a relatively small number of highly compact stars more dense than neutron stars. But if dark matter actually consists of weakly interacting massive particles (WIMPs), those are not expected to be atomic, so only 15% of the universe's mass would be atomic. I personally think that dark matter is WIMPs, so I'd say 15%.

As a side note, dark matter and dark energy together constitute more than 95% of the universe by energy density, but dark energy doesn't have mass and therefore wouldn't be considered here. Dark energy makes up about 75% of the energy density, but none of the mass, atomic or otherwise.

Answer 2

Some planets are made of diamond with the atoms tightly scrunched, perhaps pluto is made of plutonium and uranus uranium but if the known universe is the mass we can see then of course all of it, but then of course it could be all space at the same time when you consider the space between electrons of an atom you might start to wonder just how much space is between the particles of an electron

So you see, all and none

"Everything is Nothing"

Ob1 "the dreamer"

Answer 3

Not counting dark matter, the proton and the neutron are by far the most massive of the stable subatomic particles, and most of them are in atoms. I can't give you a number, but the total mass of all free alpha particles, free electrons, transitory particles, and all other non-virtual isolated particles would probably be less than .01% of all the total non-dark matter mass of the universe.

Astronomers, please comment on whether neutron stars, black holes, or other objects are common enough to affect this answer.

Answer 4

As of date all matter in the universe as we understand it constitutes only 5%. Rest of 95% is dark matter. The structure of dark matter is not known to us. Hence we can say 5% of universe is made of atoms. We need more studies to be sure of balance 95%.

Answer 5

100%

Answer 6

All of it. Little boogers have overwhelmed us. LOL