The half - life of radium-224 is 3.5 days .what fraction of the sample remain undecaye after fourteen days

We can use the formula for half-life to calculate the fraction of a sample that remains after a certain amount of time:

fraction remaining = (1/2)^(time/half-life)

In this case, the time is 14 days and the half-life is 3.5 days, so we can plug in and simplify:

fraction remaining = (1/2)^(14/3.5)
fraction remaining = (1/2)^4
fraction remaining = 1/16

Therefore, after 14 days, only 1/16th or 0.0625 of the original sample of radium-224 remains undecayed.

To determine the fraction of the sample that remains undecayed after fourteen days, we need to calculate how many half-lives have passed during that time.

Given that the half-life of radium-224 is 3.5 days, we can divide the elapsed time (14 days) by the half-life:

14 days / 3.5 days = 4

This means that four half-lives have passed in this time period.

To find the fraction that remains undecayed after four half-lives, we can use the formula:

Fraction remaining = (1/2)^(number of half-lives)

So, plugging in the number of half-lives into the formula:

Fraction remaining = (1/2)^4

Calculating the fraction:

Fraction remaining = 1/16

Therefore, after fourteen days, only 1/16 of the original sample remains undecayed.