Give preparation of `XeF_6` and `XeOF_2`.

Give the preparation Nylon 6

Give the preparation of Telfon.

Give the preparation Melamine

Give the preparation of chlorine.

Give the preparation of Neoprene and also give one use of it.

Give the preparation of carbon dioxide.

Give the preparation and uses of Orlon

Give preparation and structure of ClF_3 .

Write structures of XeF_2 and XeF_4 .

(i) Discuss the anomalous behaviour of nitrogen. (ii) Give the preparation and structure of XeF_(4) . (iii) Write short note on 'Liquation'. (iv) Why is Helium used in diving apparatus ?