The total internal energy of an object that comes from random motion of its particles.

The potential energy stored in chemical bonds of molecules.

Energy which an object possesses due motion.

The stored energy an object has due to its position.

The emission of energy as electromagnetic waves or subatomic particles.

The process of heat being transferred by touch.

The process of heat being transferred by a fluid.

An object used to help complete a task by changing the direction of motion or the amount of required force.

A device that is made up of two or more simple machines working together.

The envelope of gases surrounding the earth or another planet.

The lowest region of the atmosphere, extending from the earth's surface to a height of about 3.7–6.2 miles (6–10 km), which is the lower boundary of the stratosphere.

A colorless unstable toxic gas with a pungent odor and powerful oxidizing properties, formed from oxygen by electrical discharges or ultraviolet light. It differs from normal oxygen (O2) in having three atoms in its molecule (O3).

The outermost region of a planet's atmosphere.

The region of the earth's atmosphere above the stratosphere and below the thermosphere, between about 30 and 50 miles (50 and 80 km) in altitude.

The layer of the earth's atmosphere above the troposphere, extending to about 32 miles (50 km) above the earth's surface.

The innermost, central, and most fundamental part of a system or Earth.

A significant layer of a planetary body located between its outermost crust and its innermost core.

The process by which gases in the Earth's atmosphere trap heat, warming the planet's surface and lower atmosphere.

The layer of the Earth's atmosphere located between the mesosphere and the exosphere.