Get Answers to all your Questions

header-bg qa

Q.13.12 (b)  Find the Q-value and the kinetic energy of the emitted \alpha -particle in the \alpha-decay of

                  (b)\; _{86}^{220}\textrm{Rn}

                  Given m(_{88}^{226}\textrm{Ra})=226.02540\; u,      m(_{86}^{222}\textrm{Rn})=222.01750\; u,

                   m(_{86}^{222}\textrm{Rn})=220.01137\; u,     m(_{84}^{216}\textrm{Po})=216.00189\; u,

Answers (1)

best_answer

Mass defect is \Deltam

\Delta m=m(_{86}^{222}\textrm{Rn})-m(_{84}^{216}\textrm{Po})-m(_{2}^{4}\textrm{He})

\Deltam=220.01137-216.00189-4.002603

\Deltam=0.006877 u

1 u = 931.5 MeV/c2

Q-value=\Deltam\times931.5

=6.406 MeV

By using Linear Momentum Conservation and Energy Conservation 

Kinetic energy of alpha particle =

\frac{mass\ of\ nucleus\ after\ decay}{mass\ of\ nucleus\ before\ decay}\times Q-value

=\frac{216.00189}{220.01138}\times 6.406

=6.289 MeV

Posted by

Sayak

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads