Answer: The half life of the Element x is 9 minutes = 9x60 =540 seconds.
t(1/2) = 0.693/λ
λ = 0.693/540
λ = 0.00129
N = No.exponent(−λt)
where No is the mass of element at t = 0
and N is amount left
t is time
and λ is constant.
301 = 850 x exponential(-0.00129xt)
0.354 = exponential(-0.00129xt)
taking natural log both sides
ln(0.354) = (-0.00129 x t)
t = 805 seconds
805/60 = 13.42 minutes
Step-by-step explanation:
The half life time of any radioactive element is denoted by t(1/2) and is equal to 0.693/λ
and also to calculate the remaining amount after it decays for a time t is N = No.exponent(−λt)