How can we help?
You can also find more resources in our
Select a category
Something is confusing
Something is broken
I have a suggestion
What is your email?
What is 1 + 3?
any natural material that is used by humans, such as water, petroleum, minerals, forests and animals
a natural resource that can be replaced at the same rate at which the resource is consumed
a resource that forms at a rate that is much slower than the rate at which it is consumed
the process of recovering valuable or useful materials from waste or scrap; the process of reusing some items
a nonrenewable energy resource formed from the remains of organisms that lived long ago; examples include oil, coal, and natural gas
a liquid mixture of complex hydrocarbon compounds; used widely as a fuel source
a mixture of gaseous hydrocarbons located under the surface of the Earth, often near petroleum deposits; used as a fuel
a fossil fuel that forms underground from partially decomposed plant material