Start Carbon 14 dating denotes the amount of

Carbon 14 dating denotes the amount of

Using a device called a mass spectrometer, the scientist can now count how many carbon-14 atoms are in the wood. There are a number of other methods scientists use to answer these.

Cosmic rays enter the Earth's atmosphere all the time.

This means that the amount of carbon-14 atoms in the wood will stop being replaced and will begin to decay.

Thousands of years later, an anthropologist may find this axe and will want to know how old it is.

The interesting thing is that each isotopes decays at a constant rate. If we know how long it takes for these isotopes to decay, then we can estimate how old something is.

For example, if we had a huge block of carbon-14 sitting in our living room, aside from it being dangerous, half of this block will decay into nitrogen in 5,730 years according to How Stuff Works. It may seem kind of far-fetched so let's work through an example.

Neutrons, on the other hand, have no charge and are therefore neutral. Neutrons and protons are added to together to get what is called the atomic mass. So if we add the amount of protons and neutrons together of carbon, we should get twelve right? If you look at carbon on the Periodic Table, under the "C" symbol, we see 12.01. For many of the elements on the periodic table, the amount of neutrons matches the amount of protons.

However, there are rare species, or variants of an element, that have a different number of neutrons in them. Isotopes are usually extremely rare and therefore only add very little to the average atomic mass.

They are so rare, in the case of carbon, that their collective existence only deviates the average atomic mass from 12.00 to 12.01.