Two species of radioactive atoms are mixed in equal number. The disintegration of the first species is and of the second is / 3 . After a long time the mixture will behave as a species with mean life of approximately

Step-by-step solution

avg life = td N ₁+ td N ₂ 2 ~N ₀ where d N₁= N_ o e^ - t d t array l d N ₂= 3 ~N ₀ e ^ - 3 t dt avg. life = ₀^ t ( N ₀ e ^ - t dt + 3 ~N ₀ e ^ - 3 t dt . 2 ~N ₀ array Intergrating we got avg life = 2 2.10