Science-Tools and Machines

Natural resources are materials from the Earth that are used to support life and meet people's needs.

Any natural substance that humans use can be considered a natural resource.

Oil, coal, natural gas, metals, stone and sand are natural resources.

Other natural resources are air, sunlight, soil and water.

Burning can occur only in the presence of oxygen. 

When you place a jar over the lit candle, it continues to burn for some time while it is using the oxygen available in the jar. 

However, the oxygen inside the jar gets exhausted after some time and the candle extinguishes. 

The consumption of oxygen lowers the air pressure in the jar.

The high pressure outside pushes the water into the jar and the water level rises.