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isaiahh223gLv4
1 Dec 2022
Half life
All the information I was given is in the picture please look at them thanks and make your work is not copied off of Google
The half-life $\left(\mathrm{t}_{1 / 2}\right)$ of a radioactive substance is the amount of time required for half of the unstable, radioactive atoms in a sample to undergo radioactive decay.
This relationship is modeled mathematically through exponential decay, relating the quantity of substance initially and finally present, the mean lifetime of the decaying quantity, the decay constant, and the half-life. You will have an opportunity to work with the actual equation in more advanced math and science courses.
In this lesson, however, we will focus on understanding radioactive decay and learn how to calculate the amount of radioactive substance that will remain after an integral number of half-lives have passed away.
Example: A patient is administered 18 mg of iodine-131. How much is left after 24 days? (The half-life of iodine-131 is 8 days.)
Begin by determining how many half-lives we are considering:
We are interested in the amount of iodine-131 left after 24 days.
After each 8 days, the amount remaining is cut in half. Thus, we are interested in 24/8 = 3 half-lives.
Next, figure out how much iodine-131 remaining after each half-life:
Initially (t = 0 days ) = 18 mg
1 half-life (t = 8 days )=18 mg /2 = 9 mg
2 half-lives (t = 8 + 8 = 16 days )= 9 mg/2 = 4.5 mg
3 half-lives (t = 16 + 8 = 24 days )= 4.5mg /2 = 2.25 mg
Thus, 2.25 mg of iodine-131 will remain after 24 days
Solve the following problems:
1. An isotope of cesium-137 has a half-life of 30 years. If 5.0 g of cesium137 decays over 60 years, how many grams will remain?
2. How many grams of californium-254 will remain after 363 days if we start with 64.0 grams of this substance? The half-life of californium-254 is 60.5 days.
3. 5.0 mg of radioactive nobelium-253 was removed from the reactor to be used in an experiment. It took 291 seconds (just under 5 minutes) to get the sample from the reactor to the laboratory. How many milligrams of nobelium-253 remained upon arrival to the laboratory? The half-life of nobelium-253 is 97 seconds.
Half life
All the information I was given is in the picture please look at them thanks and make your work is not copied off of Google
The half-life $\left(\mathrm{t}_{1 / 2}\right)$ of a radioactive substance is the amount of time required for half of the unstable, radioactive atoms in a sample to undergo radioactive decay.
This relationship is modeled mathematically through exponential decay, relating the quantity of substance initially and finally present, the mean lifetime of the decaying quantity, the decay constant, and the half-life. You will have an opportunity to work with the actual equation in more advanced math and science courses.
In this lesson, however, we will focus on understanding radioactive decay and learn how to calculate the amount of radioactive substance that will remain after an integral number of half-lives have passed away.
Example: A patient is administered 18 mg of iodine-131. How much is left after 24 days? (The half-life of iodine-131 is 8 days.)
Begin by determining how many half-lives we are considering:
We are interested in the amount of iodine-131 left after 24 days.
After each 8 days, the amount remaining is cut in half. Thus, we are interested in 24/8 = 3 half-lives.
Next, figure out how much iodine-131 remaining after each half-life:
Initially (t = 0 days ) = 18 mg
1 half-life (t = 8 days )=18 mg /2 = 9 mg
2 half-lives (t = 8 + 8 = 16 days )= 9 mg/2 = 4.5 mg
3 half-lives (t = 16 + 8 = 24 days )= 4.5mg /2 = 2.25 mg
Thus, 2.25 mg of iodine-131 will remain after 24 days
Solve the following problems:
1. An isotope of cesium-137 has a half-life of 30 years. If 5.0 g of cesium137 decays over 60 years, how many grams will remain?
2. How many grams of californium-254 will remain after 363 days if we start with 64.0 grams of this substance? The half-life of californium-254 is 60.5 days.
3. 5.0 mg of radioactive nobelium-253 was removed from the reactor to be used in an experiment. It took 291 seconds (just under 5 minutes) to get the sample from the reactor to the laboratory. How many milligrams of nobelium-253 remained upon arrival to the laboratory? The half-life of nobelium-253 is 97 seconds.
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christopherc63Lv10
1 Dec 2022
