An element's atomic number defines it. An element with 17 protons will always be chlorine. However an element's mass numbers can vary, which means that it can have different numbers of neutrons.

It also tells us that chlorine has 18 neutrons (35 - 17) and, as the number of electrons and protons are equal in a neutral atom, chlorine also has 17 electrons. The relative mass of a nucleus is ...

The reaction releases a lot of heat as the ionic compound sodium chloride is formed. A sodium and chlorine atom are near each other. An electron from each atom feels the attraction from the other atom ...

the MXene surface changes into a brush-like structure. Atoms of non-noble metals migrate out and form so-called "SAC-like structures" (single atom catalyst-like). These catalysts mediate two ...