When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate of copper sulphide is obtained and the sulphuric acid so formed remains in the solution. The reaction is an example of: A) a combination reaction. B) a displacement reaction. C) a decomposition reaction. D) a double displacement reaction.

What type of questions asked from the lesson of magnetic effect of electric current 

Wavelength of green light is

A) 400-450 nm

B) 500-550 nm

C) 660-720 nm

D) 720-800 nm

What is the difference between anaerobic & aerobic respiration? Name some organism that uses the aerobic mode of respiration?

What are the main components of our environment? Explain each of them briefly.

What are examples of hydrotropism plants?