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Atomic  Structure

You’ve probably seen the image above. Its the basic representation of an atom. Although this isn’t how an atom really looks.

Its just our best known scientific representation of what an atom probably looks like.

There are 3 basic parts to any atom.

Protons. Are positively charged. These subatomic particle give the atoms a positive charge.

Neutrons. Are the same mass as a proton, but don’t have an electrical charge. Hydrogen is the only element without a neutron.

Electrons. Are negatively charged subatomic particles, which swing around the Nucleus of the atom.

What you’ll almost always see in diagrams, is the electron neatly orbiting the nucleus. However in real life electrons circle the nucleus in a random pattern. It from a cloud around the nucleus.

An electron’s negative charge is equal in strength to a proton’s positive charge. However an electron is much smaller than a proton.

As the electrons circle the nucleus, they circle it on different levels, or shells. Each shell can only hold a specific amount of electrons.

The closest shell to the nucleus (shell 1) can hold a max of 2 electrons.  

The 2nd shell holds a max of 8 electrons

The 3rd shell hold a max of 8 electrons

The 4th shell has a max of 8 electrons.

The more energy the electron has, the higher shell it is on.

The electrons on the outer shell are called valence electrons.

The goal of all atoms if to have a full outer shell. You’ll notice Fluorine has 9 electrons. This mean 2 in it’s first shell, and 7 in it’s 2nd shell.

It is only 1 away from a full second outer shell, so it is more likely to steal or share electrons to complete the shell.

On the other hand, Lithium has 3 electrons. Meaning it’s easier to loose 1 electron, than it is to find 7.

Electrons are extremely important in the generation of electricity. The movement of many electrons in a single direction creates an electric current.

Metals are good conductor because they would rather loose their electrons than gain them, to have a full outer shell.

Since these atoms are willing to loose electrons they become positively charged in a sea of electrons.

They are also extremely important in bonding. There are two main types of bonding, covalent and ionic (electrovalent).


Covalent bonding, is where the electrons are actually shared between two or more atoms in a cloud.

Ionic (electrovalent)

Ionic or Electrovalent, is where the electron from one atom is transferred to another atom.

You’ll notice the atom has now changed to an Ion (A charged atom).

It is the valence electrons which are responsible for bonding with other atoms.