Simple Dalton Atomic Model

An atom is a unit of matter that is made up of protons, electrons and neutrons.

Everything is made up of atoms. They are the smallest particle of an element and is the most basic unit of matter. Atoms are much too small to see, even with a microscope.

In the 1800’s John Dalton described his idea of the atomic structure. He believed that atoms were ‘solid spheres’. Also suggesting that many different spheres make up all of the different elements in existence.

In the centre of the atom, there is a structure called the nucleus, which is made up of neutrons and protons. The nucleus is positively charged due to the protons. Majority of the atomic mass is in the nucleus.

The electrons are thought to surround the nucleus. They orbit the nucleus in circular structures known as electron shells. The electrons have a negative charge and also have almost no mass.

Particle Charge Relative mass
Proton +1 1
Neutron 0 1
Electron -1 Almost 0

The overall charge of atom is neutral. This is due to atoms having the same number of electrons and protons.