Why fusion reaction has not been possible yet to be carried out inside laboratory.

The rate of a certain biochemical reaction catalyesd by an enzyme in human body is 10^4 times faster than when it carried out in the laboratory. The activation energy of this reaction :

Why is leaching of gold by metal cyanides carried out in the presence of oxygen? Give the chemical equation. Name the metal used as reducing agent.

Each question given below has four possible answers out of which only one is correct. Choose the correct one. veca.vecbxxveca =