Question

A certain radioactive nuclide has a half life of 50.7 years. How long does it take for 87.5% of a sample of this substance to decay? years Submit Hide Hints Hint 1 Hint 4 Hint 3 Hint 2 What percentage of the original sample has decayed after two half lives have elapsed?

Answer 1

Radioactive decay is a first order kinetics.

dl.: N = Mo(4) n= No. of Half lives - I ÑO = (1)" 105 = ()1 $=() T= Total time t1 = 50.7 years Remains N = 100-87.5 = 12.5 hide Mo= 100 = initial Nuclide ( ) ² = ()" => m=3 "n=157 T= n*50.7 = 3x50.7 | T = 521 years oll No=100 N= 1 Noz 100 m=? N = 100*(+)2 N = 25) Nalecay = No -N = 100-25 | Nodecay = 75 % Medecay = Ho-x100 = 100-NX100 7100 E 100-25100 700X100 % Melecay => 75%