This Study Mind Tutorial covers the following specification points:

CIE: 2.3.3, 2.3.4, 2.3.5

2.3.3. understand oxidation and reduction in terms of electron transfer and changes in oxidation number, applied to reactions of s- and p-block elements

2.3.4. understand oxidation and reduction in terms of electron loss or electron gain

2.3.5. know that oxidising agents gain electrons