For example, a helium atom has an atomic mass of 4, but an atomic number (or positive charge) of 2. Since electrons have almost no mass, it seemed that something besides the protons in the nucleus ...

In 1901 and 1902 he worked with Frederick Soddy to prove that atoms of one radioactive element would spontaneously turn into another, by expelling a piece of the atom at high velocity. Many ...

It is not the same as a helium atom as it does not contain any electrons but it is written with the same chemical nomenclature as a helium atom: \(_{2}^{4}\textrm{He}\) When a radioactive atom ...

The atom is neutral as it has two positive protons and two negative electrons. A helium atom that has lost or gained an electron is an ion. The ion has two positive protons but one electron so it ...

to any other He atom, a preference for being attached at those points which belong to the same diamond lattice, that is, the binding energy at a diamond point should be greater than anywhere else.