It is a liquid metal at room temperature, but it is a toxic heavy metal and hence many uses of mercury are under review or phased out.
It is manly used as a catalysts in chemical industry.
  
It is also used in insecticides, hair dyes and as an anti-knocking additive for petrol. But all these are banned by the government as Lead metal is known for detrimental to health.
  
Industrial Uses
Electrical Industry, Electronic Industry
  
Chemical Industry, Electrical Industry, Electronic Industry
  
Medical Uses
Dentistry
  
Surgical Instruments Manufacturing
  
Other Uses
Alloys, Mirror Manufacturing, Pharmaceutical Industry