So, we have a “clock” which starts ticking the moment something dies.
Obviously, this works only for things which were once living.
Radiocarbon dating is based on the fact that a radioactive isotope of carbon( Potassium argon dating is an absolute dating technique that can be used on volcanic rocks.
Radioactive potassium (40potassium) decays into argon over time, so the age of certain rocks or minerals can be discovered by measuring the amount of argon they contain.
These each have 19 protons and 21 neutrons in their nucleus.
If one of these protons is hit by a beta particle, it can be converted into a neutron.
Relative dating methods were the first dating techniques to be developed, and are still widely used.
In other words, the change in numbers of atoms follows a geometric scale as illustrated by the graph below.other carbon isotopes in the same ratio as exists in the atmosphere.
It is based on the fact that some of the radioactive isotope of Potassium, Potassium-40 (K-40) ,decays to the gas Argon as Argon-40 (Ar-40).
By comparing the proportion of K-40 to Ar-40 in a sample of volcanic rock, and knowing the decay rate of K-40, the date that the rock formed can be determined.
With 18 protons and 22 neutrons, the atom has become Argon-40 (Ar-40), an inert gas.
For every 100 K-40 atoms that decay, 11 become Ar-40.