11. Bromine is a
A. black solid
B. red liquid
C. colourless gas
D. highly inflammable gas
12. The hardest substance available on earth is
A. Gold
B. Iron
C. Diamond
D. Platinum
13. The variety of coal in which the deposit contains recognisable traces of the original plant material is
A. bitumen
B. anthracite
C. lignite
D. peat
14. Tetraethyl lead is used as
A. pain killer
B. fire extinguisher
C. mosquito repellent
D. petrol additive
15. Which of the following is used as a lubricant?
A. Graphite
B. Silica
C. Iron Oxide
D. Diamond