Question

A radioactive nucleus 'X' decays to a stable nucleus 'Y'. Then the graph of rate of formation of 'Y' against time 't' will be –

• A.
• B.
• C.
• D.

Answer 1

Answer: (C)

Answer 2

X ¾® Y

t = 0 N₀ 0

t = t N₀ – N

N_Y = N₀ – N

N = N₀ e^–lt

N_Y = N₀ (1–e^–lt)

Rate of formation of Y

̃ = N₀le^–lt

The above curve is decreasing with time.