Question

How chalcogen elememtsbare used in the eviroment or society?

Answer 1

Chalcogens are the elements of the group 16 of the periodic table: oxygen, sulphur,
selenium, tellurium and polonium.
The first element, oxygen, is the widest spread chalcogen on the Earth and the third most
abundant element in the Universe after hydrogen and helium. It constitutes 88.8% of the
ocean’s mass and 62.5% of the mass of human body. Thus, the importance of oxygen
doesn’t need to be proven: its role in living organisms is vital. In industry, the primary use of
elemental oxygen is in steelmaking. Indeed, the impurities in hot metal such as carbon (C),
silicon (Si), manganese (Mn) and phosphorus (P) are oxidised and removed during the
production of liquid steel.
Sulphur in its turn is mostly converted into sulfuric acid, which is heavily used in the chemical
industry, for example in fabrication of the fertilizers for agriculture. As well, sulphur is
necessary in nutrition: two amino acids, cysteine and methionine contain this chalcogen. 
Going down the periodic table, chalcogens become for living organism. While oxygen is not
toxic at all, sulphur itself is not toxic but some of its compounds are; selenium is toxic at high
concentrations although used as a nutrition additive diminishing the risk of cancer disease.
Selenium is used in different electric sensors and connectors, in chemistry (vulcanisation)
and in fabrication of the glass; development of pigments; in hard industry and agriculture.
Tellurium compounds are mostly used in optical disks, electronic devices, and solar cells.
Some of polonium's applications are due to its radioactivity. These metalloids are rare and
expensive, restricting their usage in industry.