Nuclear explosions produce both immediate and delayed destructive effects. Immediate effects (blast, thermal radiation, prompt ionizing radiation) are produced and cause significant destruction within seconds or minutes of a nuclear detonation. The delayed effects (radioactive fallout and other possible environmental effects) inflict damage over an extended period ranging from hours to centuries, and can cause adverse effects in locations very distant from the site of the detonation.
Further reading:
http://nuclearweaponarchive.org/Nwfaq/Nfaq5.html
http://en.wikipedia.org/wiki/Nuclear_fallout
It depends on the radioactive material. All radioactive isotopes have a property called a "half-life". This is the time it takes for half the atoms in the sample to decay. This concept is a little confusing. "Half" refers to "half of whatever's left," so after one half-life, half of the radioactive material will still be there; after two half-lives, half the original material plus half of the other half will be gone and one quarter will remain; after three half-lives one eighth will remain, and so forth. Complicating this even further is that some materials decay into OTHER radioactive materials which have their OWN half-lives, and which may then decay into YET MORE radioactive materials... As you can see, the bookkeeping can get fairly involved, even without allowing for the fact that some materials have several decay options.
I'm going to go out on a limb here and say that the question you meant to ask was "how long does a radioactive substance stay radioactive." The answer is that it depends on what the radioactive substance is. Some things decay quickly and are intensely radioactive for a short time but then fall to more or less background levels; other things decay slowly and remain radioactive for a very long time.
to determine how long it will take to half of nuclids to decay, having use in radioactive materials operations
The length of time depends on the element and isotope, but the point at which half of the sample has decayed is known as the half-life.
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).
The half-life of a radioactive isotope is defined as the time taken for the isotope to decay to half of its initial mass. So to decay to 50 percent of its initial mass will take one half-life of the isotope. One half-life of the isotope is 10 hours so the time taken to decay is also 10 hours.
No, the half life remains exactly the same throughout
It indicates how long it takes for the material to decay.
It indicates how long it takes for the material to decay.
To figure out how old something is based how long it takes elements in the sample to decay.
To figure out how old something is based how long it takes elements in the sample to decay.
If you are talking about the game made by VALVe, it is 17 chapters long how long they are depends on how long you take to beat them. It took me 10 hours on easy.If your talking about the scientific term, It's how long a radioactive material takes for it to decay 1/2 its mass, this varies form each material
Carbon-dating
they measure how long it takes for half of its unstable molecules to turn to more stable atoms, a half life
they measure how long it takes for half of its unstable molecules to turn to more stable atoms, a half life
to determine how long it will take to half of nuclids to decay, having use in radioactive materials operations
The length of time depends on the element and isotope, but the point at which half of the sample has decayed is known as the half-life.
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).
Each radioactive isotope has its own rate of decay, called the "half-life". This is the time that it takes for one-half of the radioactive elements to decay into something else. For very radioactive elements, the half-life is pretty short, but sometimes the element that id decays into is itself radioactive. It _NEVER_ completely decays, but at some point the nuclear waste is no more radioactive than the background material. Remember that some elements like uranium are naturally found in rock formations, and that elements like radon are naturally occuring in the environment. This becomes a problem in the basements moutainous areas, where radon gas accumulates and can cause lung cancers. In general, nuclear waste needs to be protected and isolated for about 50 years; after that, the residual radioactivity isn't going to be especially hazardous.