But when he tried an even smaller atom, calcium, the temperature fell again.

Just about one centimetre for relatively small atoms, yes.

A result of nuclear fission in addition to the smaller atoms produced is several neutrons.

Force yourself to break each concept into the smallest possible atom.

Virtually all of an atom is empty space, so perhaps the question should be turned on its head: why aren't atoms even smaller?

Years later I would hear of atoms, too small to be seen by men.

It is particularly important as the accurate quantum theory description of the smallest free atom, hydrogen.

This is why small atoms seldom break apart into smaller atoms.

Examples of small atoms are hydrogen, boron, carbon and nitrogen.

It is when an atom splits apart into smaller atoms.