The metal which does not react with cold as well as hot water but reacts with steam is

(1) Cu 
(2) Zn 
(3) Na 
(4) Fe

Which of the following compounds is bad conductor of electricity?

(1) Ionic compound
(2) Electrovalent compound  
(3) Covalent compound
(4) None of these

A metal is strongly heated in presence of air to form a black mass. So the metal is

(1) Potassium
(2) Platinum
(3) Copper
(4) Zinc

Calamine ore can be converted into ZnO by the process of.

(1) Dehydration
(2) Roasting
(3) Calcinations
(4) Sulphonation

Which of the following always contains mercury as one of the constituent ?

(1) Stainless steel
(2) Solder
(3) Duralumin
(4) Zinc Amalgam