Two radio-isotopes P and Q of atomic weight 10 and 20 respetively are mixedratio is found to be 1:m 4 Isotope P has a half-life of 10 day The half of isotope Q is:

Two radio-isotopes P and Q of atomic weight 10 and 20 respetively are

1.	Two radio-isotopes P and Q of atomic weight 10 and 20 respetively are mixedratio is found to be 1:m 4 Isotope P has a half-life of 10 day The half of isotope Q is:
Answer» Zero `5` day `20` day Infinite Solution :Let `WG` of each be taken then Initial mole of `P = (w)/(10)`, mole of `Q = (w)/(20)` Final mole of `P = (w_(1))/(5xx10)` Final mole of `Q = (4w_(1))/(20xx5)` For P, `(P_(N_(0)))/(P_(N))=e^(lambda_(1)t)` For `Q, (Q_(N_(0)))/(Q_(N))=e^(lambda_(2)t)` For `P :. (w xx 5 xx10)/(10xx w_(1)) = e^(lambda_(1) xx20)` ...(i) For `Q :. (w xx 20xx5)/(20XX w_(1) xx4) = e^(lambda_(1) xx20)` ...(ii) By (i) and (ii), `4 = e^(lambda_(1) - lambda_(2)xx20)` `:. 20(lambda_(1) - lambda_(2)) = log_(e) 4` `:. t = oo`