Formation of Ions

This lesson covers:

1. How ions are made
2. Why some elements are more likely to form ions than others
3. How to write equations for the ionisation of an atom

positive / negative / bigger / smaller / shell

Atoms need a full outer of electrons in order to be stable. One way they can achieve this is by gaining or losing electrons. 

Those that gain electrons become ions with a charge, whilst those that lose electrons become ions with a charge. 

Magnesium loses electrons to become an ion. Complete the equation below:

 ➔ Mg²⁺ + e^-

Atoms in group 5 have electrons in their outer shell. This means they need to gain electrons to be stable, forming an ion with a charge of . 

The transfer of electrons requires a lot of energy.

Groups 1, 2, 6 and 7 form ions very easily. This is because they only need to gain or lose a small number of electrons, and so less energy is required. 

Those in groups 3, 4 and 5 do not form ions very easily, because they need to gain or lose a larger number of electrons, and therefore more energy is required. 

more / less / time / energy

Atoms which need to gain or lose only 1-2 electrons are likely to become ions, compared to those which need to gain or lose 3-4.

This is because gaining or losing electrons requires a lot of .