21.

Galvanised iron sheets have a coating of
A. lead B. chromium
C. zinc D. tin
Answer and Explanation
Answer:C
Explanation: No answer description available for this question.
22.

Among the various allotropes of carbon,
A. coke is the hardest, graphite is the softest B. diamond is the hardest, coke is the softest
C. diamond is the hardest, graphite is the softest D. diamond is the hardest, lamp black is the softest
Answer and Explanation
Answer:C
Explanation: No answer description available for this question.
23.

The group of metals Fe, Co, Ni may best called as
A. transition metals B. main group metals
C. alkali metals D. rare metals
Answer and Explanation
Answer:A
Explanation: No answer description available for this question.
24.

Heavy water is
A. deuterium oxide B. PH7
C. rain water D. tritium oxide
Answer and Explanation
Answer:A
Explanation: No answer description available for this question.
25.

The chemical (ethyl mercaptan) added to the otherwise odourless LPG cooking gas for imparting a detectable smell to the gas is a compound of
A. bromine B. fluorine
C. chlorine D. sulphur
Answer and Explanation
Answer:D
Explanation: No answer description available for this question.