Oxygen Cycle

compound

anysubstance consisting of two or more atoms (elements) that are chemically combined.

cycle

a periodically repeated sequence of events; a series of events or operations that repeat regularly in the same order.

oxidation

the most common way in which oxygen combines with other substances.

oxygen

a colorless, ordorless gas. The most common element on earth. Combines easily with many other substances.

ozone

a colorless gas whose molecules are composed of three oxyben atoms.

Photosynthesis

the chemical process by which green plants make their own food. They do this by combining carbon dioxide and water in the presence of chlorophyll and light. Oxygen is given off as a byproduct. One "side" of the oxygen cycle.

respiration (cellular)

chemical reactions that release energy for the suppor of cell life. Carbon diooxide and water are given off as waste. One "side" of the oxygen cycle.

Ozone which acts as pollution

found near the ground

__ oxygen molecules bond together to form oxygen molecule

two

__ oxygen molecules bond together to form ozone

three

Land plants take in oxygen

through tiny holes in their outer surfaces.

Earth's rainforests are important because

they produce about one-third of the world's oxygen.

Oxygen cycle

contains both respiration and photosynthesis

combustion

a form of rapid oxidation.

Carbon dioxide and water

Waste products of respiration