1. Fuels are substances that burn to produce heat as a form of energy.   2. The energy they produce in the form of heat is turned into electricity or used to drive machines.   3. Thus, they provide convenience which is...

  Calcium Carbonate 1. Calcium is a reactive metal. Therefore, it does not exist in its pure form in nature.   2. Calcium tends to combine with other elements to form compounds.   3. Calcium carbonate is one of the many useful...

  1. Photograph 6.4 shows some beautiful natural quartz crystals and some useful electronic chips in a computer.   2. Both are made of silicon.   3. Silicon is an element. It is a metalloid (mettaloid is an element with...

  1. Elements can be classified into two main groups, namely metals and non-metals.   2. Metals are extracted from the mineral ores found within the Earth's crust.   3. Properties of metals are:     (a) Good...

  1. Earth's resources are materials found in nature that are useful or necessaryto living things. Minerals are non-renewable Earth's resources.   2. The Earth's crust contains vast mineral resources. Materials used in...