Oxygen is one of the primary components that allows air to be breathable to people and it began forming in the atmosphere approximately one billion years ago. Until the ozone layer formed, most life on the planet was restricted to the oceans.Continue Reading
The Earth's atmosphere formed in three stages:
As the planet formed during the first 500 million years of its existence, the air was a combination of vapor and gases that escaped from the Earth's interior. The hydrosphere formed about four billion years ago and through a process much like condensation created the first oceans.
Blue-green algae appeared one billion years ago and were the first sea organisms. They fed off the carbon dioxide in the oceans and excreted oxygen as a waste product. The oxygen eventually accumulated in the atmosphere, where it began to interact with the ultraviolet rays of the sun. The interaction formed ozone molecules, which serve to absorb UV rays and partially block them from reaching the ground. The ozone layer is thought to have reached a point at which it can block biologically lethal forms of UV radiation by 600 million years ago. As the ozone layer formed, oxygen levels increased to 10 percent, which is half the concentration found in the air today.Learn more about Chemistry
Oxygen therapy is necessary for people whose lungs lack the ability to absorb sufficient oxygen naturally from the air as a result of conditions such as chronic obstructive pulmonary disease, lung disease, sleep apnea, heart failure and asthma, according to Healthline. Patients with pneumonia, dysplasia, cystic fibrosis and traumatic respiratory system also need oxygen therapy. The therapy may take place at the doctor's office or at home, and may be occasional or continuous depending on the patient's condition.Full Answer >
The air that people breathe is almost identical to atmospheric air, consisting of about 78 percent nitrogen and 21 percent oxygen. The last 1 percent of air composition is made of several different gases like argon, helium, carbon dioxide, methane, hydrogen and water vapor.Full Answer >
Chemical differentiation describes the process by which heavier, molten elements like iron and nickel sank to the center of the Earth and lighter elements like silicon, oxygen and aluminum populated the surface of the planet 4.5 billion years ago, according to Indiana University-Purdue University Fort Wayne. Scientists theorize that gravity caused the chemical elements to separate into different parts of the Earth.Full Answer >
Oxygen is a non-flammable gas that is colorless and odorless. It has a melting point of 54.36 Kelvin and a boiling point of 90.19 Kelvin. Oxygen speeds the rate of combustion by acting as an oxidizing agent.Full Answer >