Latent heat
Boiling water. Image credit chemistryland.com ZIMSEC O Level Combined Science Notes: Latent Heat
- when heat is applied to a material the temperature of that material increases
- if the heat is removed and the material is allowed to cool then there is a decrease in that material’s temperature
- however […]
Farming compounds have a higher population density. Image credit
Robert Moffat. Image credit MediaWiki ZIMSEC O Level History Notes:The Colonisation of Zimbabwe:Concession seekers who visited Matebeleland between 1870 and 1900 and the treaties they signed 
Burning metals in air, Magnesium oxide.
The reactivity series. Image credit
Burning sulpher ZIMSEC O Level Combined Science Notes: Experiment: Making acidic and alkaline solutions
Copper and its alloys. Image credit zzhi.com ZIMSEC O Level Combined Science Notes:Copper and its alloys 

Conductors and Insulators. Image credit sci-toys.com ZIMSEC O Level Combined Science Notes: Conductors and insulators