Why do we call oxygen-sulphur group chalcogen family?

Why do we get rains?

Assertion (A) : Oxygen - sulpher group in the periodic table is called as chalcogen family. Reason (R) : Ores of many metals are oxides and sulphides.

Why do we call rayon is cellulose fibre?

Which group elements are called halogen family ?

Why do we conserve biodiversity?

Why elements of group 17 are called halogens?

Why do we call some fibres artificial man made fibres?

Why do we call coal and petrol are exhaustible resources?

What do we call the larger level of ecosystem?

Why are group - 16 elements called chalcogens ?