Inorganic Chemistry/First Glance At Subatomic Particles

First Glance At Subatomic Particles

This lesson provides very basic information about protons, neutrons and electrons. If you think you are familiar with the concepts, move to the next lesson, From Big Bang to Atoms.

A hydrogen (¹H) atom. It has one proton and one electron. Protons have positive charge. Electrons have negative charge

Every substance around us is made from very small particles, called molecules. Each molecule contains several atoms. You can think atoms as balls. Many balls attached to each other make a molecule.

Inside an atom, there are even smaller 'balls', called protons, neutrons and electrons. Protons and neutrons are attached to each other, making the nucleus of the atom. This nucleus oscillates very fast. Orbiting this nucleus are one or more electrons. Electrons are much smaller and lighter than protons and neutrons. The charge of an electron is -1.602 x 10^-12 C. The charge of a proton is 1.602 x 10¹². That is why electrons are often depicted as rotating around the nucleus. Neutrons have no charge.

Some information

Subatomic Particles	Symbol	mass / mu	Charge / e
Proton	p	1.0073	+1
Neutron	n	1.0087	0
Electron	e-	5.486 x 10-4	-1

e is the elementary charge, equals 1.602176565(35)×10^-19 C . A proton having a charge of one means its charge is one time the elementary charge.

m_u is the atomic mass constant, equals 1.660 538 782(83)×10^-27 kg. An electron having a mass of 5.486 x 10^-4 means its mass is 5.486 x 10^-4 times the atomic mass constant.