KCET2018PhysicsNuclear Physics
The half life of tritium is ( 12.5 ) years. What mass of tritium of initial mass ( 64 ~g ) will remain undecayed after ( 50 ) years?
Options
- A( 32 mg )
- B( 8 mg )
- C( 16 mg )
- D( 4 mg )
Correct answer
D. ( 4 mg )
Step-by-step solution
Given, half-life of tritium =12.5 years; initial mass =64 mg ; time, t =50 years We know that N=N₀ e^ - t and = 0.693 T_ 1 / 2 = 0.693 12.5 years N N₀ =e^ -0.693 12.5 50 N N₀ =e^ -2.772 =0.0625 N=N₀ 0.0625=64 0.0625 mg N=4 mg Thus, 4 mg of tritium will remain undecayed after 50 years