Give reasons for the following observations :
Why `SF_(4)` undergoes hydrolysis but not `SF_(6)`?
Or `SF_(6)` is inert towards hydroysis.
`SF_(6)` is much less reactive than `SF_(4)`.
Or (i) `SF_(4)` is easily hydrolysed whereas `SF_(6)` is not easily hydrolysed.
(ii) Sulpher exhibits greater tendency for calenation than selenium.
(iii) Sulpher has a higher tendency for catenation than oxygen.