We wouldn’t exist because there would be no planets. If there were something in space other than mostly nothing, there would be drag on things orbiting stars. Their orbits would decay and they’d crash into the stars.

Practically, it is impossible to make a perfect vacuum. A perfect vacuum is defined as a region in space without any particles. The first problem is that the container itself will radiate photons (which in turn can create electron positron pairs in the vacuum) if it is not kept at a temperature of 0’K.

Outer space has very low density and pressure, and is the closest physical approximation of a perfect vacuum. But no vacuum is truly perfect, not even in interstellar space, where there are still a few hydrogen atoms per cubic meter.

As most people who have done any amount of physics know, no object is truly solid; go small enough and you will find vast amounts of space containing atoms, electrons, etc, all relatively enormous distances away from each other.

You can’t destroy a particle. You can produce new particles or radiation by colliding protons (or neutrons…), but, in the sense that they explode and disappear, it is impossible. Nevertheless, you can get muons, gamma-rays, or, more interesting, you could be able to “see” the quarks inside the protons for a moment.

(Phys.org)—As an elementary particle, the electron cannot be broken down into smaller particles, at least as far as is currently known.

In time, the electron reacts with the proton via its overlapping portion, collapses to a point in the nucleus, and disappears as it becomes part of the new neutron. Because the atom now has one less proton, electron capture is a type of radioactive decay that turns one element into another element.