Ncert Exercises & Solutions

Draw a graph showing the variation of decay rate with number of active nuclei.

Hint: The decay rate is directly proportional to the active nuclei.

Step 1: Find the relation between the decay rate and the active nuclei.

We know that, rate of decay

= \frac{- d N}{d t} = λ N

where decay constant

(λ)

is a constant for a given radioactive material. Therefore, the graph between

N and \frac{d N}{d t}

is a straight line as shown in the diagram.