Define radio activity.

Define the activity of a given radioactive substance. Write its SI unit.

Define the Activity of a radioactive sample. Write its S.I. unit. A radioactive sample has activity of 10000 disintegrations per second (dps) after 20 hours. After next 10 hours its Activity reduces to 5000 dps. Find out its half-life and initial activity.

Half life period of a radio active element is 1500 years. Find the value of disintegration constant interms of second.

State about JFM with reference to Chipko movement. Write two effects of radio active substances on human.

Define activation energy . What is threshold energy ?

Write differences between order and molecularities of a reaction. Define activation energy. What is temperature co-efficient of a reaction.

The active phase, also called metabolic or energetic phase with most cytogenetic activity is

A 280 days old radioactive shows an activity of 6000 dps, 140 days later it's activity becomes 3000 dps. What was its initial activity ?

mention the activity of pencillin.

What is biological magnification? Write two effects of radio-active pollution on human health.