Explain potassium 40 dating

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. 1979, 1986 © Harper Collins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Cite This Source potassium-argon dating A method of radiometric dating, involving analysis of the ratio of potassium 40 (a radioactive isotope of potassium) to argon (the product of radioactive decay of potassium 40) in a given sample.

method is based upon the decay of radioactive potassium-40 to radioactive argon-40 in minerals and rocks; potassium-40 also decays to calcium-40.

The site also must be geologically meaningful, clearly related to fossil-bearing rocks or other features that need a good date to join the big story.

If one of these protons is hit by a beta particle, it can be converted into a neutron.Potassium (K) is one of the most abundant elements in the Earth's crust (2.4% by mass).One out of every 10,000 Potassium atoms is radioactive Potassium-40 (K-40).The potassium-argon age of some meteorites is as old as 4,500,000,000 years, and volcanic rocks as young as 20,000 years old have been measured by this method.Carbon dating is used to determine the age of biological artifacts up to 50,000 years old.That is, a fresh mineral grain has its K-Ar "clock" set at zero.The method relies on satisfying some important assumptions: Given careful work in the field and in the lab, these assumptions can be met.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.In terms of atomic weight, it is located between two more stable and far more abundant isotopes (potassium 39 and potassium 41) that make up 93.25% and 6.73% of the Earth total potassium supply respectively.With a half-life of 1,251 billion years, potassium 40 existed in the remnants of dead stars whose agglomeration has led to the Solar System with its planets.