any material in nature that people use and value
a natural resource that can be restored
a resource that cannot be replaced
the act of processing used or abandoned materials for use in creating new products
Natural resources that can be converted into energy
a nonrenewable energy resource that forms in the Earth's crust for millions of years
an oily, dark-colored, flammable liquid found in the earth, consisting mainly of a mixture of various hydrocarbons.
Process in which rock and soil are stripped from the Earth's surface to expose underlying material.
precipitation that contains acids due to air pollution