Question

An atom is described as a nucleus of protons and neutrons surrounded by what?

Answer 1

`"Electrons..............."`

Explanation:

So there is a massive nuclear core, and around this massive core, the electrons are presumed to whizz about, to orbit, in a (generally) predictable way.

With increasing degrees of sophistication, the electrons are confined to various energy levels, shells in other words, and within the shell there are prescribed sets of orbitals (and such orbitals accommodate 2 electrons). Electrons can combine with the electrons of other atoms to form chemical bonds: regions of high electron density between 2 positively charged atomic nuclei.