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.
If a sample of a radioactive isotope has a half life of 1 day, then there will be one half of the original sample left after one day, and one quarter (one half of one half) left after two days, and one eighth (one half of one half of one half) after three days.
That's two half lives. At the end of the first day, half the original material has decayed. At the end of the second day, half of what's left, or one quarter, more will have decayed.
So one quarter of the original material will be left. Note that the other three quarters is probably "still there", it'll just be a different nuclide.
that would depend on the halflife, which you did not give.
1/8
Half life is the time taken for approximately half of the available nuclei in a sample of radioactive material to decay into something else. It's a characteristic of the isotope, for example, the half life of the isotope of iodine, I131 is 8.08 days. Half lives can vary from fractions of a second to thousands of years.
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.
A half-life is the time it takes for half the original quantity of a given radioisotope to decay. If we are given a sample of one kind of radioactive material, the time it takes for half of it to undergo radioactive decay is the half-life of that radioisotope. It's a statistically derived figure, but scientists have arrived at some very accurate figures to denote the half-life of different radioactive isotopes.The half-life of an unstable material is a constant which is characteristic of exponential decay. This follows because at any time in the decay process the number of disintegrations per second is proportional to the number of atoms of the isotope present, and this is generally unaffected by any physical influence on the material.The half life of a radioactive isotope (radioisotope) is the amount of time required before half of the original mass of the isotope has decayed. For example, the radioisotope Uranium-238 i has a half-life of 4.46 billion years, therefore, if you have 100g of uranium-238 today in 4.46 billion years you will only have 50g.Radioactive substances undergoes decaying process by emitting alpha and beta particles from its nuclei of its own atoms. The time required to desintegrate half of the amount of a radioactive substance is its half life.
The following formula can be used to calculate half-life (t1/2):t1/2 = (t ln 1/2)/(ln mf / mi)t = time that has passedmf = the final or remaining mass of undecayed samplemi = the initial or original mass of undecayed sample(The fraction mf / mi is of course equivalent to the fraction of undecayed sample remaining, in case you are given the fraction remaining rather than specific masses.)Note: You can also use base-10 logarithms instead of natural logarithms.The half-lives of radioactive isotopes vary between a tiny fraction of a second, and more than 1015 years.(see related link to a list of half-lifes)
The time it takes for a half of the element to decay. In Example: Technetium-99 has a half life of 6 hours. If you begin with a sample of 100g, then after 6 hours you will have 50 grams, at 12 hours you will have 25 grams and so on; however it will NEVER reach 0 (it will remain in exponentially small ammounts because of the asymptote in the graph). This specific exponential decay is shown by the equation y=100(0.5)((1/6)x)
the same
Half life is the time taken for approximately half of the available nuclei in a sample of radioactive material to decay into something else. It's a characteristic of the isotope, for example, the half life of the isotope of iodine, I131 is 8.08 days. Half lives can vary from fractions of a second to thousands of years.
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.
One quarter.
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.
A half-life is the time it takes for half the original quantity of a given radioisotope to decay. If we are given a sample of one kind of radioactive material, the time it takes for half of it to undergo radioactive decay is the half-life of that radioisotope. It's a statistically derived figure, but scientists have arrived at some very accurate figures to denote the half-life of different radioactive isotopes.The half-life of an unstable material is a constant which is characteristic of exponential decay. This follows because at any time in the decay process the number of disintegrations per second is proportional to the number of atoms of the isotope present, and this is generally unaffected by any physical influence on the material.The half life of a radioactive isotope (radioisotope) is the amount of time required before half of the original mass of the isotope has decayed. For example, the radioisotope Uranium-238 i has a half-life of 4.46 billion years, therefore, if you have 100g of uranium-238 today in 4.46 billion years you will only have 50g.Radioactive substances undergoes decaying process by emitting alpha and beta particles from its nuclei of its own atoms. The time required to desintegrate half of the amount of a radioactive substance is its half life.
average atomic massof an element=(Atomic mass of first isotope X % of that isotope) + (Atomic mass of second isotope X % of the second isotope)
12.5%
It can vary from tiny fractions of a second to several sextillion years.
Elements that have their atomic weights in parentheses are unstable and radioactive, some of these will decay in less than a second. The atomic mass in the parentheses is the most stable isotope of the element.
Deuterium, it has 1 neutron and one proton.
That would be "half-life". That means, how long does it take for half of the atoms in a sample to decay (convert into some other type of atom). Depending on the specific isotope, this "half-life" can be anything from a tiny fraction of a second, to billions of years.