The decay constant of a radio isotope is λ. If A1 and A2 are its activities at times t1 and t2 respectively, the number of nuclei which have decayed during the time (t1-t2)

Question

The decay constant of a radio isotope is λ. If A1 and A2 are its activities at times t1 and t2 respectively, the number of nuclei which have decayed during the time (t1-t2) (A) A1t1-A2t2 (B) A1-A2 (C) (A1-A2)/ λ (D) λ (A1-A2)

Tardigrade Admin · Accepted Answer

A1=λ N1 at time t1 A2=λ N2 at time t2 Therefore, number of nuclei decayed during time interval (t1-t2) is N1-N2 =([A1-A2]/λ)

Q. The decay constant of a radio isotope is $λ$ . If $A_{1}$ and $A_{2}$ are its activities at times $t_{1}$ and $t_{2}$ respectively, the number of nuclei which have decayed during the time $(t_{1} - t_{2})$

$A_{1} t_{1} - A_{2} t_{2}$

$A_{1} - A_{2}$

$(A_{1} - A_{2}) / λ$

$λ (A_{1} - A_{2})$

$A_{1} = λ N_{1} a t t im e t_{1}$
$A_{2} = λ N_{2}$ at time $t_{2}$
Therefore, number of nuclei decayed during time interval $(t_{1} - t_{2})$ is
$N_{1} - N_{2} = \frac{[ A _{1} - A _{2} ]}{λ}$

Q. The decay constant of a radio isotope is λ. If A1​ and A2​ are its activities at times t1​ and t2​ respectively, the number of nuclei which have decayed during the time (t1​−t2​)

A1​t1​−A2​t2​

A1​−A2​

(A1​−A2​)/λ

λ(A1​−A2​)