caffeine has a half-life of 4.6 hours in the human body.. How long would it take 125 milligrams tritium to decay to 22 milligrams?
Pray tell what does caffeine have to do with tritium?
For tritium,
k = 0.693/t1/2
You will need to look up the half-life of tritium unless that is the "caffeine" half-life.
Substitute k into the below equation.
ln(No/N) = kt
Nl = 125
N = 22
k = from above calculation.
t = time. Solve for this. Note that the unit for time and the unit for half-life must be the same.
To determine how long it would take for 125 milligrams of tritium to decay to 22 milligrams, we need to calculate the number of half-lives that need to occur.
1. Determine the initial amount of tritium: 125 milligrams.
2. Determine the final amount of tritium: 22 milligrams.
3. Calculate the ratio of the final amount to the initial amount: 22 milligrams / 125 milligrams ā 0.176.
4. Use the formula for the number of half-lives: n = log(base 2) of (final amount / initial amount).
n = log(base 2) of 0.176
n ā -2.61
The calculated value for n approximately equals -2.61. However, half-lives are always positive whole numbers, so in this case, we round up to the nearest whole number to ensure we end up with a positive value.
5. Round up the value of n: -2.61 rounded up equals -2.
6. Multiply the absolute value of n by the half-life of tritium (4.6 hours): 2 * 4.6 hours = 9.2 hours.
So, it would take approximately 9.2 hours for 125 milligrams of tritium to decay to 22 milligrams.