Radioactive Decay

nuclear decay is when the nucleus of an atom is broken apart. because the number of protons has changed, so has the element. this usually happens with large nuclei, which tend to be more unstable (radioactive) than smaller nuclei.

Carbon dating is only accurate up to about 60 000 years.

It makes the assumption that the concentration of C-14 in our atmosphere has been relatively constant for the last 60 000 years. If this assumption is correct then carbon dating is accurate. It cannot be used for samples less than around 100 years due to the testing of atomic bombs which altered the 14C levels. Calibration curves are used to date the age of know antiquities (they are mentioned in historical documents so their age can be known). Other than that there are inaccuracies of a few percent as the object gets older than several thousand years.

There are three types: Beta decay, alpha decay, and gamma decay/gamma rays. They are all dangerous if exposed to a high amount of radioactive matter. When the radioactive isotope undergoes beta, alpha, and gamma decay, there is an emission of a beta particle, alpha particle, and gamma ray (respectively). In highly radioactive matter, there are often trillions of radioactive isotopes that emit these particles and/or rays - and they are very high-energy once emitted. However, they are only dangerous when exposed to a high amount.

Carbon 14 is the isotope that is used for carbon dating.

The equation for the alpha decay of 222Rn is: 86222Rn --> 84218Po + 24He

Where He represents the alpha particle, which can also be viewed as a Helium nucleus.

• mass number decreases by 4
• atomic number decreases by 2
• the nuclei recoil quite strongly (compared to other modes of decay) due to the large mass of the alpha particle

it is used by scientist to to calculate a rock's age

depends on the element it is decaying. could be the result of over exposure to R.A materials over time or it could be an infection within a person which would mean they are dying because there is no cure for that type of toxity

Statistically carbon-14 atoms decay at a constant rate.

transmutation of elements... the thing alchemists sought to do

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.

The equation for the beta decay of 87Kr is:

3687Kr --> 3787Rb + -10e

where -10e represents a negative beta particle or electron.

For most practical cases, there is no way to do so. For instance, the temperature has hardly any influence on such a half-life.However, in certain extreme circumstances it is possible to make an atom decay (or fuse with other atoms) - for example, with temperatures of millions of degrees, or bombarding the atoms with neutrons or some other particles.

the process of bone-scan imaging, using radiometric dating, radium paint that makes watch dials glow in the dark using carbon-14 to determine fossil ages

Carbon dating is mainly used by archaeologists to date recent finds as the technique is only accurate for 50,000 to 60,000 years in the past. To date fossils, or rather the rocks in or near where the fossils are found, we use radioactive isotopes which have a much greater half life.

When a radioactive isotope of an element releases a radiation particle the sub-atomic structure of it's nucleus changes. If an alpha particle is released the nucleus loses 2 protons and 2 neutrons, making it a new, lighter and smaller atom and therefore a different element. If a beta particle is released one of the neutrons in the nucleus releases an electron and becomes a proton so the atom's mass does not change significantly but t does become a different element.

Uranium is the radioactive element used in nuclear power plants these days. This element has a very high energy content.

Everything has carbon in it. When the organism dies, it begins to disintegrate. We know the rate at which things disintegrate at, so we can determine how much carbon is left and then apply a scientific formula and figure out how old the organism is. Radioactive dating works much the same.

The equation for the beta decay of 24Na is: 1124Na --> 1224Mg + -10e

where the e is a negative beta particle or electron.

This is how carbon dating works: Carbon is a naturally abundant element found in the atmosphere, in the earth, in the oceans, and in every living creature. C-12 is by far the most common isotope, while only about one in a trillion carbon atoms is C-14. C-14 is produced in the upper atmosphere when nitrogen-14 (N-14) is altered through the effects of cosmic radiation bombardment (a proton is displaced by a neutron effectively changing the nitrogen atom into a carbon isotope). The new isotope is called

Since the atomic number of Sr is less than 90, Sr undergoes beta decay.

Beta decay is when the element decays into another element and a neutron actually breaks apart (sort of) into an electron and proton; the proton attaches to the other element, but the electron stays alone.

Thus:

90------>90 Y+e0-1

38 Sr--->39 Y+e

*there should only be one e, and the 0 and -1 should be in front, just like with the elements, but the format deletes the extra spaces so i put it like that for clarity's sake. sorry!