The half life of a radioactive sample is 6.93 days.after how many days will only one -tenth of the sample be left behind?
To find out after how many days only one-tenth of the radioactive sample will be left, we need to use the concept of half-life.
The half-life is the time it takes for half of the radioactive substance to decay. In this case, the half-life of the sample is given as 6.93 days.
To find the time it takes for one-tenth of the sample to be left, we need to determine how many half-lives are required.
Let's start by dividing the total time passed by the half-life. Since we want to find the time when only one-tenth of the sample remains, we can set up the equation:
Number of half-lives = (total time passed) / (half-life)
Number of half-lives = 1/10
We can now solve for the total time passed:
(total time passed) = (Number of half-lives) * (half-life)
(total time passed) = (1/10) * (6.93 days)
(total time passed) = 0.693 days
After solving the equation, we find that it will take 0.693 days for only one-tenth of the sample to be left.
.1=e^-.693t/6.93
.1=e^-.1
ln.1=.1t
t=-10ln(.1)