Not sure what you mean by "had-lives". After 3 half lives, approx 1/8 would remain.
1st half life: 0.5 = 1/2
2nd half life: 0.5*0.5 = 0.25 = 1/4
3rd half life: 0.5*0.5*0.5 = 0.125 = 1/8
You need to calculate (1/2) to the power 3.
0.5 x 0.5 x 0.5, or 0.125 (one eighth).
The remaining is 1/8.
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.
Mono isotopic elements are stable isotope of an element.From 80 isotopic elements there are 26 radioactive elements discovered up till now.These mono isotopic may or may not be radioactive if they are radioactive they have halve lives.
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.
the half-life of chlorine 36 is 400,000 years. 200,000 years is 1/2 of a half life. in general, the formula to calculate the fraction of remaining amount is 1/2^n, where n represents the number of half-lives that have passed. in this case, n=1/2, or 0.5, therefore the remaining fraction is 1/2^0.5. Use your calculator and you will find that this is 0.707, or about 71% of the original amount. hope this helps
The most amount of lives taken by hurricanes is 300,000.
The fraction that remains is 1/8.
1/8 of the original amount remains.
An eighth remains.
3.1 %
Not sure what you mean by "had-lives". After 3 half lives, approx 1/8 would remain.
Approx 1/8 will remain.
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.
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.
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.
Half-life is 5.27 years; 21 / 5.27 = 3.99, or almos 4 half-lives; (1/2)4 = 1/16.
No. Only radioactive elements have half-lives, the half-life is the time that it will take for half of the atoms in a sample of a radioactive isotope to decay into another element or isotope. This is a constant property of the isotope and does not depend on the sample size. Stable isotopes never decay.
The remainder is 2-p or 0.5p of the original amount.