Question

The thickness of ozone is measured as
(a) parts per billion
(b) Dobson units
(c) parts per million
(d) decibel.

Answer 1

Answer:

[b] Dobson units

Explanation:

A Dobson unit of gas is equal to a layer of gas, at the surface of the Earth, with a thickness of one hundredth of a millimeter.

The ozone in the atmosphere is about 300 Dobsons.

Answer 2

✴ The thickness of ozone is measured as Dobson units.

$\underline{\boxed{\bf{\red{Ozone\:layer\:depletion:}}}}$

▪ Depletion in the concentration of ozone over a restricted area as over Antarctica is called ozone hole.

▪ Ozone depleting substances (ODS) are substances which react with ozone in the stratosphere and destroy the same. Major aerosol pollutant present in jet plane emissions is chloroflurocarbon.

▪ Chloroflurocarbon produces active chlorine in the presence of UV rediation. These destroy ozone, converting it into oxygen. Besides CFCs used as coolants in air conditioners and refrigerators, cleaning solvents, aerosol propellants and foam insulation and hydrocarbons are also responsible for O3 depletion.

Thinning of ozone layer increases the amount of UV-B radiations reaching the earth which affect photosynthesis, as well as damage nucleic acid in living organisms.