The periodic table shows all the elements


Capacity of each shell:

1st : 2

2nd: 8

3rd: 16

4th: 32

5th: 50

(outer shell: 8 electrons)



Molecules and chemical bonding


Ionic Bonds

Covalent Bonds

Octet rule: Part I Part II Part III

The hydrogen molecule

Lewis diagrams

Oxidation numbers

Molecular orbitals

Electron density



The Chemical bond

Hydrogen molecule

The animation below shows how the hydrogen molecule is formed:

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Hydrogen is the most simple atom: it has only 1 proton in the nucleus and 1 electron moving around it. The hydrogen molecule is also the simplest molecule: it consists of 2 hydrogen atoms bound together.

The animation shows how 2 independent hydrogen atoms, if get close enough, can stick together and form a molecule. In that case, the electrons that previously orbited each of the atoms, start to move around both nuclei. The electrons are responsible for the chemical bond between the two atoms.

The chemical bonding provided by the 2 electrons in this case must outweigh the electrostatic repulsion between the 2 positive nuclei, so that a stable molecule is formed.

This process can be represented using the Lewis notation:


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