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 ...

Part of Physics (Single Science) Unit 1: Atomic and nuclear physics Most of the mass and all of the positive charge of an atom is in the nucleus. Most of an atom is empty space, (a vacuum). In 1897, ...