The proton number (Z) of an atom is the number of protons it contains. All the atoms of a particular element have the same proton number (number of protons). The atoms of different elements have ...
Atoms are very small. They have a radius of around 1 × 10 10 metres. This symbol shows that chlorine has 35 particles in the nucleus (protons and neutrons), 17 of which are protons. It also tells us ...