Mrs Roberts: What do you think you're made of? Mr Spellman: Big question. Grit, determination, hard-working, handsome, charming, funny. Mrs Roberts: Well, I guess. But you're actually made of atoms.

Chlorine naturally exists as two isotopes, \(_{17}^{35}\textrm{Cl}\) (chlorine-35) and \(_{17}^{37}\textrm{Cl}\) (chlorine-37). The abundance of chlorine-35 is 75% ...

Conventional neutron numbers are based on the approximations that the mass of the electron is zero and that those of the proton and neutron are each equal to unity. It was shown, by using the exact ...

For the first time those little numbers that appear beneath some of the commonest elements in the periodic table boxes are about to change from a single value to an interval of numbers An ...