# Half-Life of Radioactive Isotopes

Half-Life of Radioactive Isotopes

Half-Life of Radioactive Isotopes

Choose one of the isotopes from the list below:

Name of your chosen radioactive isotope:___________________________________________________

Convert the half-life that is given in days, into weeks and years. Round your answers to 4 decimal

places.

Half-Life in Days: Half-Life in Weeks: Half-Life in Years:

Moving forward, we will use the half-life in days, so t will be measured in days. Using the formula for

exponential decay (𝐴 = 𝐴0𝑒 𝑘𝑡) and the half-life for your radioactive isotope, calculate k. Make sure to

get your value of k to 8 decimal places.

𝑘 = _______________________

Write an equation for your radioactive isotope plugging in k, but no specific value of t (for example, 𝐴 =

𝐴0𝑒 −.00027154𝑡).

𝐴 = _________________________________

Now, use your equation to find how long it will take for the radioactive isotope to decay to 20% of its

original amount. Round your answer to the nearest tenth.

_________________days