The following come close:
* thulium-168, 93.1 days
* fermium-257, 100.5 days
* thulium-170, 128.6 days
If a radioactive sample contains 1.25g of an isotope with a half-life of 4.0 days, then 0.625g (1/2) of the isotope will remain after 4.0 days, 0.3125g (1/4) after 8.0 days, 0.15625g (1/8) after 12.0 days, etc. AT = A0 2(-T/H)
The half-life of the radioisotope Fe55 is approximately 2.7 years. This means that after 2.7 years, half of the original amount of Fe55 will have decayed into other elements.
The half-life of cobalt-57 is about 271.74 days.
After 10 days, 1/2 of the original isotope will remain since its half-life is 5 days. This means 6kg of the original isotope will remain after 1 half-life, which remains the same after 10 days since another half-life has passed.
A half life is the time for one half of a radioactive material to decay. Different materials have half-lives of different lengths. Some last only a fraction of a second. Some have a half life of hundreds of thousands of years. Unless you tell us what the material is, we can only answer "that all depends."
After 8.1 days, three half-lives have passed for Au-198 (2.7 days/half-life * 3 half-lives = 8.1 days). Each half-life reduces the number of atoms by half, so remaining atoms = 800 atoms * (1/2)^3 = 100 atoms.
If a radioactive sample contains 1.25g of an isotope with a half-life of 4.0 days, then 0.625g (1/2) of the isotope will remain after 4.0 days, 0.3125g (1/4) after 8.0 days, 0.15625g (1/8) after 12.0 days, etc. AT = A0 2(-T/H)
Thorium-234 has a half-life of 24.1 days. How much of a 100-g sample of thorium-234 will be unchanged after 48.2 days?
Alpha decay to californium 253. The half life of fermium 257 is 100.5 days.
The answer is 2. If after one half-life only half of the element remains, then after another half-life half of what was there only remains. So a half of a half is a quarter (or a fourth). So that's 2 half-lives.
After 8.1 days, three half-lives have passed (8.1 days / 2.7 days = 3). With each half-life, the number of atoms is halved. Therefore, starting with 800 atoms, after three half-lives there would be 800 / 2 / 2 / 2 = 100 atoms remaining.
The half-life is 2 days. You start with 100 grams. In one half life, you will lose 50 grams and have 50 grams remaining. In a second half-life, you will lose 25 of the 50 grams and have 25 grams left. You will have lost 75 grams of a 100 gram sample of radioactive material and have only 25 grams of it left after two half-lives. That means there are two half-lives from 9 a.m. Monday to 9 a.m. Friday. That's 4 days for 2 half-lives, or 2 days for one half-life.
After 48,2 days the amount of Th-234 will be 25 g.
The half-life of the radioisotope Fe55 is approximately 2.7 years. This means that after 2.7 years, half of the original amount of Fe55 will have decayed into other elements.
The half-life of cobalt-57 is about 271.74 days.
Your question is related to the half life of drug. Above drug has half life of about 20 hours. So it will be out of your system by 5 times it's half life. It means 100 hours. So it will be practically out of your system in about four days from last dose.
The length of four half-lives of radon-222 can be calculated by multiplying the half-life duration by four. Since the half-life of radon-222 is 3.823 days, four half-lives would be 4 × 3.823 days, which equals approximately 15.292 days.