Define radio activity.

Derive an expression for the half-life of a radio active nuclide.

Write the relation between Half-Life and Mean-Life of radio active element.

Define energy of activation. Draw a diagram of energy profile to show the influence of a positive catalyst on the energy of activation of a reaction.

Define abiotic stress. Write two suspended activities in animals against abiotic stresses with suitable examples

The radioactive isotope of carbon used in radio carbon dating is :

The activity of radioactive isotope decreases with: