Which one, among the following atmospheir gases, filters out most of the ultraviolet radiation of the Sun?

Ozone (O3) is the primary atmospheric gas responsible for filtering out the majority of the Sun's harmful ultraviolet (UV) radiation. While it constitutes less than 0.00005% of the atmosphere's volume, it is concentrated in the stratosphere between 20 km and 30 km, forming the ozone layer [4]. This layer acts as an invisible shield, absorbing nearly all high-energy UV-C radiation and the majority of UV-B radiation [2]. The absorption process involves UV light splitting oxygen molecules (O2) into atoms, which then combine with other O2 molecules to form ozone; this cycle effectively 'filters' the radiation and converts it into heat energy [3]. Without this protective layer, high levels of UV-B would reach the Earth's surface, causing significant damage to human health, plants, and marine ecosystems [3].

Sources

1. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 20: Earths Atmosphere > Ozonosphere > p. 276
2. [4] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 20: Earths Atmosphere > Ozone (O3) > p. 272
3. [1] https://ozone.unep.org/ozone-and-you
4. [2] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 1: BASIC CONCEPTS OF ENVIRONMENT AND ECOLOGY > Structure of the Atmosphere > p. 8