First slide

Radio activity

Question

A sample of radioactive element has a mass of 10 gm at an instant t = 0.The approximate mass of this element in the sample after two mean lives is

Moderate

A

2.50 gm
B

3.70 gm
C

6.30 gm
D

1.35 gm

Solution

$M = M_{0} e^{- λt}; given t = 2 (\frac{1}{λ}) \Rightarrow M = 10 e^{- λ (\frac{2}{λ})} = 10 {(\frac{1}{e})}^{2} \Rightarrow M = 1.35 gm$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App