Wiki User
∙ 14y agoAfter 28 years your sample halves, ie becomes 38 mg. In another 28 years it will have halved again to 19 mg, so your answer is 56 years
It may not seem important, but you should remember that your sample is not evaporating. The actual 76 mg sample will still have almost all of its mass after 56 years. But by that time only 19 mg of it will be strontium-90. The rest of the sample will still be there, but it will have become Zirconium-90 which is stable.
Wiki User
∙ 14y ago5730 years (approx).
The answer depends on 3240 WHAT: seconds, days, years?
A decade is 10 years, so decades refers to multiples of 10 years. It is a term that is generally used for a long period of time, but often less than 100 years, as then you would start using the term centuries.
They were not invented because they predated the first human beings. They existed at least millions of years before there was anyone to "invent" them.All novae produce radioactive elements and these decay exponentially. So exponential decay predates the formation of the solar system.I am not sure, but stellar fusion may be exponential. But, in any case, there are life forms on earth, like bacteria, that exhibit exponential growth. These bacteria, and therefore exponential growth, predate human beings by a few million years.They were not invented because they predated the first human beings. They existed at least millions of years before there was anyone to "invent" them.All novae produce radioactive elements and these decay exponentially. So exponential decay predates the formation of the solar system.I am not sure, but stellar fusion may be exponential. But, in any case, there are life forms on earth, like bacteria, that exhibit exponential growth. These bacteria, and therefore exponential growth, predate human beings by a few million years.They were not invented because they predated the first human beings. They existed at least millions of years before there was anyone to "invent" them.All novae produce radioactive elements and these decay exponentially. So exponential decay predates the formation of the solar system.I am not sure, but stellar fusion may be exponential. But, in any case, there are life forms on earth, like bacteria, that exhibit exponential growth. These bacteria, and therefore exponential growth, predate human beings by a few million years.They were not invented because they predated the first human beings. They existed at least millions of years before there was anyone to "invent" them.All novae produce radioactive elements and these decay exponentially. So exponential decay predates the formation of the solar system.I am not sure, but stellar fusion may be exponential. But, in any case, there are life forms on earth, like bacteria, that exhibit exponential growth. These bacteria, and therefore exponential growth, predate human beings by a few million years.
I'll say 300 years = 10 half-lives. Look at it backwards. Start with 1g, and double it every time you go back 30 years. (1) x (2)10 = 1,024 which is where you want to be. Since it took 10 doublings, that's 10 half-lives.
A sample of 187 rhenium decays to 187-omium with halflife of 41.6 billion years. If all 188 osmium are normalized isotopes.
Half-life of 2000 years means that after 2000 years, half of the sample will decay - so of course the other half of the sample is still around.Half-life of 2000 years means that after 2000 years, half of the sample will decay - so of course the other half of the sample is still around.Half-life of 2000 years means that after 2000 years, half of the sample will decay - so of course the other half of the sample is still around.Half-life of 2000 years means that after 2000 years, half of the sample will decay - so of course the other half of the sample is still around.
700 milliion years. The definition of half-life is the period of time during which one-half of the atoms of an element undergo decay into other elements.
It will take two half-lives or about 60.34 years for three-fourths of a Cs-137 sample to decay.
It would take 4 half-lives for a 4.0 mg sample of X to decay to 0.50 mg. Since the half-life is 2.0 years, it would take 8.0 years for this decay to occur.
The time it takes for half of a radioactive sample to decay is known as the half-life. Each radioactive element has a unique half-life, which could range from fractions of a second to billions of years. The half-life remains constant regardless of the size of the initial sample.
The half-life is 700 million years !
100 grams
To determine the amount of radium that will decay in 5000 years, we need to find the number of half-lives that occur in that time period. Since the half-life of radium is 1602 years, approximately 3 half-lives occur in 5000 years. After 3 half-lives, the initial 35g sample will decay to approximately 4.375g.
56 years
First, it isn't very accurate to talk about a radioactive "element"; you should talk about radioactive isotopes. Different isotopes of the same element can have very different behavior in this sense. For example, hydrogen-1 and hydrogen-2 are stable, while hydrogen-3 is not (half-life about 19 years).Individual atoms, in a radioactive isotope, will decay at a random moment. The half-life refers to how long it takes for half of the atoms in a given sample to decay (and convert to some other type of isotope).
700 million years