Bromine is a
The hardest substance available on earth is
The variety of coal in which the deposit contains recognisable traces of the original plant material is
Tetraethyl lead is used as
Which of the following is used as a lubricant?
The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is
The gases used in different types of welding would include
The property of a substance to absorb moisture from the air on exposure is called
In which of the following activities silicon carbide is used?
The average salinity of sea water is
When an iron nail gets rusted, iron oxide is formed
Galvanised iron sheets have a coating of
Among the various allotropes of carbon,
The group of metals Fe, Co, Ni may best called as
Heavy water is
