Name an ore of zinc other than zinc oxide. By what process can this ore be converted to zinc oxide.

10 Give reasons for the following
i. Na, K and Ca metals form hydrides by combination with hydrogen gas, but most other metals do not.
ii. Aluminium easily combines with oxygen but still it can be used for making kitchen utensils. 11 i) Among iron and aluminium which rusts easily?
ii) What are the conditions, necessary for rusting of iron? 13 What property of hydrogen is observed in the following experiments?
i) Balloon, filled with hydrogen, floats.
ii) Pop sound is heard when a burning splint is introduced at the mouth of hydrogen filled jar.
iii) When black cupric oxide is heated in a stream of hydrogen, reddish colour is obtained. 14 Select the non-metals amongst the following 
i) Bismuth   ii) Sulphur   iii) Arsenic   iv) Hydrogen.