High School

Calculate the activity due to Po-218 formed after 20 minutes. The half-life of Po-218 is 3.05 minutes.

Answer :

The activity due to the Po-218 formed after 20 minutes is 1.62.

The radioactive decay equation for Po-218 is given as;`Po-218 -> ? + alpha

The half-life of Po-218 is given as 3.05 minutes, which means that half of the atoms decay in that time.

We can use this to find the decay constant, λ.`t1/2 = 0.693/λ

`Rearranging to find λ:`

λ = 0.693/t1/2``λ = 0.693/3.05 = 0.2271 min^-1

We can now use this to calculate the activity of Po-218 formed after 20 minutes. The general formula for radioactive decay is;

N = N0 e^(-λt)`Where;N0 = Initial number of radioactive atomsN = Remaining number of radioactive atoms after time tλ = Decay constantt = Time elapsed

We know that N0 = 150, and t = 20 minutes.

Substituting these values and solving for N;

N = N0 e^(-λt)` `= 150 e^(-0.2271 × 20)` `= 150 e^(-4.542)` `= 150 × 0.0108` `= 1.62

Therefore, the activity due to the Po-218 formed after 20 minutes is 1.62.

Learn more about activity with the given link,

https://brainly.com/question/1289354

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