What Is Ozone Layer? How It Helps Human Beings.? The Ozone Layer, we can say it as Protector of Life from Harmful UV Rays. Here we are discussing about Ozone layer, The Protector.
The Ozone Layer..
Ozone (O3) is a gas primarily found in the stratosphere, an upper layer of Earth’s atmosphere.
Although it makes up only a tiny fraction of the atmosphere, this layer is critically important because it shields flora and fauna on Earth from the Sun’s harmful ultraviolet (UV) radiation.
Ozone molecule..
An ozone molecule (O3) consists of three oxygen atoms chemically bonded together. Like any chemical bond, the bonds within an ozone molecule can be broken when a specific amount of energy is supplied to it.
How It Protects from Harmful UV Rays
The electromagnetic spectrum includes many types of radiation, such as infrared rays, visible light, and UV rays. The protective mechanism of the ozone layer involves the absorption of these energetic UV rays.
When a highly energetic UV ray strikes an ozone molecule, the energy from the ray is absorbed, causing one of the chemical bonds to break.
This process, called photodissociation, converts the ozone (O3) into a stable dioxygen molecule (O2) and a highly reactive nascent (atomic) oxygen atom (O).
The nascent oxygen atom is very unstable. This atom quickly reacts with another dioxygen molecule (O2) in the atmosphere, restoring the ozone molecule (O3).
This continuous cycle of ozone being broken down and reformed absorbs the dangerous UV radiation, preventing most of it from reaching the Earth’s surface.
Ozone Layer depletion
Recently, the ozone layer has experienced thinning, leading to what are commonly called “ozone holes,” which allow more UV rays to penetrate to the Earth’s surface.
This depletion is primarily caused by emissions of chlorofluorocarbons (CFCs) and similar ozone-depleting substances. These gases are light and stable enough to rise into the stratosphere.
Once there, the UV rays break them down, releasing chlorine atoms. The chlorine atom (Cl) acts as a catalyst, reacting with the nascent oxygen (O) or the ozone (O3) itself.
For example, a chlorine atom can react with ozone, breaking it apart which gives ClO and O2.
The chlorine oxide (ClO) then reacts with a free oxygen atom from another ozone and forms Chlorine(Cl) and stable dioxygen(O2).
Because the chlorine atom is regenerated in the second step, a single chlorine atom can repeatedly break down thousands of ozone molecules, preventing the ozone layer from restoring itself effectively.
As this continues over time, the concentration of ozone depletes, leading to the formation of ozone holes.
