- The state of coal, with lowest carbon content is anthracite coal.
- A unit of electricity means “Kilowatt hour”.
- “Urbanization” means rapid growth of cities.
- Carbon monoxide emission is associated with the burning of coal.
- Solar energy stored in material such as wood, grain, sugar and municipal waste is Biomass.
- The world faces energy crises because world demand for energy will increase.
- A fuel cell combines hydrogen and oxygen to produce electricity, heat and water.
- Fossils are the dead remains of living organism.
- Petroleum is mixture of petrol, diesel and petroleum gas.
- A source of energy such as coal, oil and natural gas is called non-renewable sources.