ELECTRON

Electron Microscope

The atom comprises an nucleus, like a central sun, with one or more electrons revolving about it like planets. The electron is a charge of negative electricity; whether it is actually a material particle we do not really know, for its mass is infinitesimal compared with that of the nucleus.

The latter is positively charged, and the normal atom keeps just enough electrons about its nucleus to make it electrically neutral. Unlike charges attract each other, while like charges repel each other.