91.
Diamonds are glittering and attractive because light incident on them undergoes

92.
If lime water is kept in the air, it turns milky due to presence of :

93.
Diamond is harder than graphite because of :

94.
The gas used to extinguish fire is

95.
Which among the following coal contains 90 per cent of carbon?

97.
Carbon dioxide is

98.
Hardest allotrope of carbon is

99.
Diamond is lustrous because

100.
Dry ice is