one to each chlorine atom. Calcium becomes a +2 ion and each chlorine becomes a -1 ion. The +2 calcium ion and the two -1 chloride ions attract each other and form an ionic bond and the compound ...

The slideshow shows how a covalent bond forms between a hydrogen atom and a chlorine atom, making hydrogen chloride. A simple molecule contains only a few atoms, so the sizes of atoms and simple ...

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.