Question

11. A 150 gram sample of radon-222 goes through alpha decay. The half-life of

radon-222 is 3.82 days. How much radon will be left after 3.82 days?

Answer 1

The correct answer is - 75 grams.

Step-by-step explanation:

Half-life is the amount of time that is used by the given amount of substance or element to make it half of the initial amount of a particular radioactive substance.

Equation for alpha decay for radon

`^222_(86)Rn\Rightarrow^(218)_(84)Po`

we need to calculate the left amount of radon after given time

using formula half life

`N(t)=N_(0)e^(-\lambda t)`

`\lambda =(0.693)/(3.82)`

`\lambda=0.1814`

`N(3.82)=150* e^(-0.1814*3.82)`

`N(3.82)=75.0\ g`

Thus, the left amount of radon is - 75 grams.