Iodine 131 is radioactive and has a half life of about 8 days.
After 32 days there would be approximately 5 milligrams remaining
After 76 seconds, half of the radium-222 would have decayed (its half-life is about 3.8 days). Therefore, the quantity of radium-222 remaining in the 12-gram sample would be 6 grams.
At 2.7 days, half of the 800 atoms (400 atoms) would have decayed. At 8.1 days, three half-lives have passed, so only ( \frac{1}{2} \times \frac{1}{2} \times \frac{1}{2} = \frac{1}{8} ) of the original sample remains. Therefore, there are 100 atoms of Au-198 remaining in the sample after 8.1 days.
Iodine-131 has a half-life of about 8 days.
If a sample of radioactive material has a half-life of one week the original sample will have 50 percent of the original left at the end of the second week. The third week would be 25 percent of the sample. The fourth week would be 12.5 percent of the original sample.
Hi, Each half-life means the mass of the sample has decreased by 1/2 its mass. Thus; After 1 half-life, 1/2 the sample has decayed. After 2 half-lives 3/4 of the sample has decayed. Hope this helps.
After 9 days, the population of ladybugs would double every 3 days, so it would double 3 times. 2^3 = 8. Therefore, the population at the end of 9 days would be 30 ladybugs x 8 = 240 ladybugs.
The mass is 1,075 g.
12.5 g
The half-life of thorium-234 is about 24 days. Therefore, it would take approximately 96 days for one-sixteenth of the original 54.2 g sample of thorium-234 to remain.
The mass is 1,075 g.
After 48,2 days the amount of Th-234 will be 25 g.
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?
A half-life of a radioisotope is the time required for half of a sample to decay. In this case, a 50-g sample becoming 25 g after 18 days indicates that the half-life of the radioisotope is 18 days, as the sample has decreased to half its original amount in that time.
At 8.1 days, 400 atoms of Au198 would remain in the sample. This is because after 8.1 days, two half-lives of Au198 have passed, reducing the initial 800 atoms to 400.
18 days
After 76 seconds, half of the radium-222 would have decayed (its half-life is about 3.8 days). Therefore, the quantity of radium-222 remaining in the 12-gram sample would be 6 grams.
At 2.7 days, half of the 800 atoms (400 atoms) would have decayed. At 8.1 days, three half-lives have passed, so only ( \frac{1}{2} \times \frac{1}{2} \times \frac{1}{2} = \frac{1}{8} ) of the original sample remains. Therefore, there are 100 atoms of Au-198 remaining in the sample after 8.1 days.