Chapter 5 “Earth’s Resources” Science Vocabulary Chapter 5 “Earth’s Resources”

mineral a solid, natural material made from nonliving substances in the ground

luster the way a mineral reflects light from its surface

hardness a measure of how well a mineral resists scratching

Sedimentary rock a rock that forms from sediments

Igneous rock a rock that forms as the lava cools and hardens

Metamorphic Rock a rock that forms when sedimentary and igneous rocks change under heat and pressure without melting

Rock cycle the changing of rocks over time from one type to another

soil a mixture of bits of rock and once living parts of plants and animals

Soil horizon each layer of soil

humus the part of the soil that is made of decayed organic materials

topsoil the dark, top layer of soil, rich in humus and minerals, in which organisms live and most plants grow

pollution the addition of harmful materials to soil, air, or water

conservation the preservation or protection of natural resources

Fossil fuel a fuel formed from the remains of ancient forms of life

Nonrenewable resource a resource that cannot be replaced within a short period of time or at all

Renewable resource a resource that can be replaced in a short period of time

reservoir an artificial lake that is built to store water

smog a type of air pollution formed by particles produced by burning fossil fuels

ozone a form of oxygen that makes a layer in the atmosphere that screens out much of the Sun’s dangerous radiation

Alternative energy source a source of energy other than the burning of a fossil fuel

recycle to make new objects or materials from old objects or materials