Define non renewable source of energy with examples.

Non renewable sources of energy are defined as the source of energy which cannot be reproduced and cannot be used forever. Non renewable source are coal, mineral oil, nuclear energy. 

Nonrenewable energy resources include coal, natural gas, oil, and nuclear energy. Once these resources are used up, they cannot be replaced, which is a major problem for humanity as we are currently dependent on them to supply most of our energy needs.Nonrenewable resources are usually considered bad for the environment. Most nonrenewable energy resources produce carbon dioxide as a byproduct. The CO2 gets trapped in the atmosphere and is the main cause of climate change, according to most climatologists. ... Economically, nonrenewable resources pose a problem as well.

There are four major types of nonrenewable resources: oil, natural gas, coal, and nuclear energy. Oil, natural gas, and coal are collectively called fossil fuels. Fossil fuels were formed within the Earth from dead plants and animals over millions of years—hence the name “fossil” fuels. They are found in underground layers of rock and sediment. Pressure and heat worked together to transform the plant and animal remains into crude oil (also known as petroleum), coal, and natural gas.