For example hydrogen has the atomic number of one, helium two, lithium three etc. The first energy level (the one nearest the nucleus) can hold a maximum of 2 electrons with the others being able ...

Helium is notoriously hard to contain because, like hydrogen, it is a tiny little atom even by atomic standards. It also expands about 750 times when it turns into a gas, according to the post’s ...

E. Rutherford has briefly restated the arguments for considering that radio-active phenomena are probably associated with atomic degradation, and that, as a rule, the loss of an atom of helium ...