Are protons, neutrons and electrons totally solid?
“Solid” isn’t really a meaningful term at the scale at which these particles exist. They are not little round balls, or even bigger round balls. They are merely clouds of probability of differnt sizes. Like clouds in the sky, they look solid from a distance but go all soft-edged and indeterminate when you get up closes. It is the interaction of these clouds that creates the illusion we call solidity. The electron may nor be in a fixed place, but it knows it doesn’t want to stay anywhere near another electron – unless it has a nice friendly proton to keep it company. Protons don’t like each other either – unless they have roughly the same number of neutrons to keep them company. Netrons don’t give a damn about each other, but will happily hang out with some protons – as long as there ae not too many extra protons. The way all of these effects interact leads to quite regular patterns – like the jocks hanging out in one corner of the dance hall, the nerds in another, and the wallflowers a
