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 ...

DEEP in the heart of every atom lurk protons, tiny particles from which the chemical elements were forged, first in the searing heat of the big bang and then in the nuclear furnaces of stars. The ...