Oxygen Cycle Research Paper

CHEMICAL PROCESSES IN ATMOSPHERE, SOIL AND WATER.

ATMOSPHERE

INTRODUCTION

The earth's atmosphere is a very thin layer covered around a very large planet. The thin covering of air that surrounds our planet is a mixture of gases, with different physical properties. The atmosphere protects us by filtering out poisonous cosmic rays, powerful ultraviolet (UV) radiation from the Sun, and even meteors on collision course with Earth. Two gases make up the earth's atmosphere which are nitrogen ( ), which comprises 78% of the atmosphere, and oxygen ( ), which accounts for 21%. Another 1% is made up of various trace gases. The atmosphere is divided into four layers which are the troposphere, stratosphere, mesosphere, and thermosphere.

Oxygen cycle is a biogeochemical cycle. Biogeochemical cycle is the movement of matter through the biotic and the abiotic spheres of the ecosystem. In the oxygen cycle, oxygen atoms present in the earth circulate through a series of complex processes. The oxygen cycle elaborates how oxygen circulates in various forms through nature. Oxygen occurs freely in the air, trapped in the earth’s crust as chemical compounds or dissolved in water.

Oxygen is also used during decomposition, combustion and oxidation. The circulation of oxygen is through four main reservoirs including the atmosphere (air), the biosphere (living things), hydrosphere (water) and the lithosphere (earth’s crust). In the oxygen cycle, the main dynamic factor is the photosynthesis which is the process whereby green plants and algae make their own food by use of solar energy, water, and carbon dioxide to give off oxygen as a by-product.

Hence, for oxygen to remain in the atmosphere, it has to circulate through various forms of nature which is fundamentally termed as the oxygen cycle. The circulation depends on the various activities on Earth.

Steps involved in oxygen cycle

• Plants release oxygen into the atmosphere as a by-product of