The Simple Atomic Model

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

All matter is made up of atoms. They are the smallest particles of an element and represent the most basic units of matter. Atoms are so small that they cannot be seen, even with a microscope.

At the centre of the atom lies a structure called the nucleus, composed of protons and neutrons. The nucleus is positively charged due to the protons. The majority of the atomic mass is in the nucleus.

The image depicts the structure of an atom. At its centre, there are several spheres: some are orange with a positive sign, representing protons, while others are grey, representing neutrons. Orbiting around this nucleus are blue spheres on blue elliptical paths, symbolising electrons. On the right, a legend explains the components: an orange sphere with a positive sign for the proton, a grey sphere for the neutron, and a blue sphere for the electron. The overall design illustrates the fundamental components of an atomic structure.

Electrons surround the nucleus and orbit it in layers known as electron shells. The electrons have a negative charge and almost no mass.

ParticleChargeRelative mass
Electron-1Almost 0

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

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