Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and halons destroy the earth’s protective ozone layer, which shields the earth from harmful ultraviolet (UV-B) rays generated from the sun.
What breaks CFCs apart in the stratosphere?
The UV light in the stratosphere breaks up the CFCs. They release chlorine, and these free chlorine atoms rip oxygen atoms off of ozone, leaving ordinary oxygen gas.
Which element of CFC is mainly responsible for destroying ozone layer?
Photodissociation of the chlorofluoromethanes in the stratosphere produces significant amounts of chlorine atoms, and leads to the destruction of atmospheric ozone.”
How CFCs damage the ozone layer?
Once in the atmosphere, CFCs drift slowly upward to the stratosphere, where they are broken up by ultraviolet radiation, releasing chlorine atoms, which are able to destroy ozone molecules. … When sunlight returns in the spring, the chlorine begins to destroy ozone.
Which gas does not deplete ozone layer?
Fluorinated gases (F-gases) have been introduced as substitutes for ODS in many sectors such as refrigeration and air conditioning applications. F-gases include hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6). These gases do not deplete the ozone layer, but they are greenhouse gases.
How is ozone formed in stratosphere?
Stratospheric ozone is formed naturally through the interaction of solar ultraviolet (UV) radiation with molecular oxygen (O2). The “ozone layer,” approximately 6 through 30 miles above the Earth’s surface, reduces the amount of harmful UV radiation reaching the Earth’s surface.
Did CFCs cause the ozone hole?
Ozone depletion occurs when chlorofluorocarbons (CFCs) and halons—gases formerly found in aerosol spray cans and refrigerants—are released into the atmosphere (see details below). … CFCs and halons cause chemical reactions that break down ozone molecules, reducing ozone’s ultraviolet radiation-absorbing capacity.
Where is the ozone hole?
What is it? The Antarctic ozone hole is a thinning or depletion of ozone in the stratosphere over the Antarctic each spring. This damage occurs due to the presence of chlorine and bromine from ozone depleting substances in the stratosphere and the specific meteorological conditions over the Antarctic.
Does the stratosphere contain the ozone layer?
The ozone layer is the common term for the high concentration of ozone that is found in the stratosphere around 15–30km above the earth’s surface. It covers the entire planet and protects life on earth by absorbing harmful ultraviolet-B (UV-B) radiation from the sun.
In which sphere ozone layer depletion is found?
5. In which sphere Ozone layer depletion is found? Ozone layers depletion was found to be done in the Stratosphere. The major reason for depletion of Ozone was chlorofluorocarbons found in ACs and Refrigerators.
Why do temperatures decrease in the troposphere and increase in the stratosphere?
The troposphere is heated from the ground, so temperature decreases with altitude. Because warm air rises and cool air sinks, the troposphere is unstable. In the stratosphere, temperature increases with altitude. The stratosphere contains the ozone layer, which protects the planet from the Sun’s harmful UV radiation.
Why is ozone only in stratosphere?
The concentration of ozone varies with altitude. … Ozone in the stratosphere absorbs most of the ultraviolet radiation from the Sun. Without ozone, the Sun’s intense UV radiation would sterilize the Earth’s surface. Ozone screens all of the most energetic, UV-c, radiation, and most of the UV-b radiation.
Why does ozone stay in the stratosphere?
Most ozone resides in the stratosphere (a layer of the atmosphere between 10 and 40 km above us), where it acts as a shield to protect Earth’s surface from the sun’s harmful ultraviolet radiation. With a weakening of this shield, we would be more susceptible to skin cancer, cataracts and impaired immune systems.
Does UV destroy ozone in air?
UV light will create ozone from atmospheric oxygen at short wavelengths of less than 240 nanometers (nm). UV light will also destroy ozone and break ozone back down into atomic oxygen (O) and diatomic oxygen (O2) at wavelengths from about 200 nm to 315 nm.
Is the ozone hole in the north or south pole?
It is one of the world’s great environmental success stories, but it was briefly punctured in the spring of 2020 when a rare second ozone hole formed over the North Pole, the largest ever to do so. The Arctic ozone loss was the product of an unusually cold and long-lasting polar vortex.
Which of the following depletes ozone layer?
NO and freons are responsible for ozone layer depletion.
Which gas is responsible for ozone layer depletion around Earth Mcq?
The correct answer is Chlorofluorocarbons. Chlorofluorocarbons(CFC) are responsible for ozone layer depletion. Ozone gas is continuously formed by the action of UV rays on molecular oxygen and also degraded into molecular oxygen in the stratosphere.
How is ozone formed in the stratosphere quizlet?
Ozone is formed in the stratosphere by the reaction of ultraviolet radiation striking an oxygen molecule. This results in the oxygen molecule splitting apart and forming atomic oxygen (O2 + hv = O + O). Atomic oxygen can now react with molecular oxygen to form ozone (O+O2 = O3).
Where is stratospheric ozone depletion highest?
The annually occurring ozone hole over the Antarctic had rapidly grown from mid-August and peaked at around 24 million square kilometres — one of the largest so far — in early October 2020.
What are the reactions for stratospheric ozone formation and stratospheric ozone depletion?
The term ozone depletion means that the destruction of O3 exceeds the creation of O3. When present together in the stratosphere, chlorine (Cl) and ozone quickly react to produce chlorine oxide. Bromine can also act as a catalyst to destroy stratospheric ozone.
What gases destroy the ozone layer?
Ozone depleting substances
- chlorofluorocarbons (CFCs)
- halons.
- carbon tetrachloride (CCl4)
- methyl chloroform (CH3CCl3)
- hydrobromofluorocarbons (HBFCs)
- hydrochlorofluorocarbons (HCFCs)
- methyl bromide (CH3Br)
- bromochloromethane (CH2BrCl)
Does CO2 destroy the ozone layer?
Carbon dioxide has no direct effect on ozone, unlike CFCs and HFCs. Higher levels of carbon dioxide, however, do have an indirect effect on the ozone layer in the stratosphere. … But near the poles and in the upper stratosphere, CO2 is increasing the amount of ozone by preventing nitrogen oxide from breaking it down.
Does methane deplete the ozone layer?
Yes, methane released into the atmosphere has a destructive effect on the ozone layer.