Give reasons for the following
i. Silicon counts among metalloids
ii. Carbon is not used for making aluminium from aluminium oxide.
iii. For making hydrogen by reaction with hydrochloric acid, granulated zinc is preferred to a block of zinc.

i. Silicon shows properties of both metals and non-metals and hence silicon counts among metalloids.
ii. Carbon has less affinity for oxygen than Aluminium and hence it cannot eliminate oxygen from Aluminium oxide.
iii. Zinc granules are preferred to a block of zinc because it offers a large surface area for the reaction with the acid.