Question

In a radioactive decay, let N represent the number of residual active nuclei, D the number of daughter nuclei, and R the rate of decay at any time t. Three curves are shown in Fig. The correct ones are –

• A. 1 and 3
• B. 2 and 3
• C. 1 and 2
• D. All three

Answer 1

Answer: (D)

All three

Answer 2

N = N₀e^–lt, D = N₀ (1 – e^–lt)

R= R₀e^–lt, $= \frac { \mathrm { R } _ { 0 } \mathrm { e } ^ { - \lambda \mathrm { t } } } { \mathrm { N } _ { 0 } \mathrm { e } ^ { - \lambda \mathrm { t } } } = \frac { \mathrm { R } _ { 0 } } { \mathrm {~N} _ { 0 } } = \lambda$

= const