Activation energy is the least possible amount of energy (minimum) which is required to start a reaction or the amount of energy available in a chemical system for a reaction to take place.
Catalysts can lower the activation energy and increase the reaction rate without being consumed in the reaction. The lower the activation energy for a reaction, the faster the rate. Thus enzymes speed up reactions by lowering activation energy.
If light travels from oil to water at an angle, what happens to the direction of the light ray in water with respect to the normal, is it moves away from the normal.
