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 ...

It is a very comprehensive framework backed by extensive experimental evidence and is the foundation of modern particle physics. The Standard Model extends ... electrons in an atom orbit the ...

An atom is so small that a single drop of water contains more than a billion atoms. Although tiny, atoms are mostly empty ...