0
Not sure what you mean by "had-lives". After 3 half lives, approx 1/8 would remain.
What else can I help you with?
How much of a 400-gram sample of K40 is left after 2 half-lives?
After the first half-life, you will have one half of the starting amount. After a second half-life period, you'll be down to one quarter. Of the part that radioactively decays, about 11% of it will decay to 40Ar, and the remainder to 40Ca. Of your total sample of ordinary potassium, only 0.012% will be 40K. The half-life of 40K is about 1.3x109 years.
How long does it take for this radioactive material to decay through 2 half-lives?
It will take twice the half-life of the radioactive material for it to decay through two half-lives. If the half-life is 1 hour, it will take 2 hours for the material to decay through 2 half-lives.
The half-life of actinium 227 is 21.772 years After 50 years how much of a 1500 g sample will remain radioactive?
After 50 years, 1500 g of actinium-227 will have undergone approximately 2.3 half-lives (50 years / 21.772 years per half-life). This means that approximately 25% (50% decayed after 1 half-life, and 50% of the remaining amount decays after the second half-life) of the original sample will remain radioactive, so there will be around 375 g of actinium-227 remaining.
Determine the amount of time it takes for three fourths of a radioactive sample of an isotope of bromine to decay the half-life of the isotope is 16.5 hours?
The half-life of the isotope is 16.5 hours, so it takes 16.5 hours for half of the sample to decay. To find the time it takes for three fourths of the sample to decay, you would calculate 2 half-lives (2 x 16.5 hours) as three fourths is equal to 1.5 times the original amount (1 + 0.5). Therefore, it would take 33 hours for three fourths of the sample to decay.
Is oxygen stable or radioactive?
Oxygen, under normal conditions, is non-radioactive. But there are traces of radioactive isotopes present which makes the oxygen slightly radioactive. Additionally, these isotopes have long half-lives, so the radiation given off will not be a lot within a period of time.
After three half-lives what fraction of a radioactive sample remains?
1/8 of the original amount remains.
What percentage of a radioactive sample remains after 5 half-lives?
After 5 half-lives, 3.125% (or 1/2^5) of a radioactive sample remains. Each half-life reduces the sample by half, so after 5 half-lives, there is only a small fraction of the original sample remaining.
Why After three half-lives what fraction of a radioactive sample remains?
After three half-lives, only 1/8 (or 12.5%) of the original radioactive sample remains. This is because each half-life reduces the amount of radioactive material by half, so after three half-lives, you would have (1/2) * (1/2) * (1/2) = 1/8 of the original sample remaining.
What fraction of a sample remains after three half lives?
An eighth remains.
What fraction of a radioactive sample remains after three half-lives?
Not sure what you mean by "had-lives". After 3 half lives, approx 1/8 would remain.
What fraction of a radioactive sample decays after three half lives?
If I take a radioactive sample of 400 moles of an unknown substance and let it decay to the point of three half-lives I would have 50 moles left of the sample. 1/2 of what is left will decay in the next half-life. At the end of that half-life I will have 25 moles left of the unknown substance or 4/25.
After three half-lives what fraction of a radioactive sample will remain?
Approx 1/8 will remain.
What part of a radioactive sample remains unchanged after 2 half lives?
After 2 half lives, 25% of the original radioactive sample remains unchanged. This is because half of the sample decays in each half life, so after 1 half life, 50% has decayed, and after 2 half lives, another 50% has decayed, leaving 25% unchanged.
What fraction of a radioactive sample remains after one half-life?
Half of the original sample of a radio isotope remains after a half-life period. After two half-life periods, one-fourth of the radio isotope remains.
Is a radioactive sample has decayed until only one eighth of the original sample remains unchanged how many half lives have elapsed?
Three half lives have elapsed. This can be determined by calculating how many times the original sample size must be halved to get to one eighth: (1/2) * (1/2) * (1/2) = 1/8.
How can half lives be shortened?
Half life of an element can't be changed.. It is a characteristic of a radioactive element which is independent of chemical and physical conditions.. Half life is that time in which half of radioactive sample( i.e., a radioactive element) decomposes. So no matter what amount you take half life of an element remains same.
Which fraction of an original 20.00-gram sample of nitrogen-16 remains unchanged after 36.0 seconds?
Nitrogen-16 has a half-life of about 7.13 seconds. After 36.0 seconds, there would be 3 half-lives. Therefore, 1/2 * 1/2 * 1/2 = 1/8 of the original sample remains unchanged.
