Potassium 40 radioactive dating
But Ramsay had an advantage over Cavendish: he could use spectroscopy, which did not exist in Cavendish's time.Spectroscopy is the process of analyzing light produced when an element is heated.
The magnesium or calcium combines with nitrogen to form a nitride: A little argon always occurs as an impurity with nitrogen. The number written to the right of the element's name is the mass number.The spectrum (plural: spectra) of an element consists of a series of colored lines and is different for every element.Ramsay studied the spectrum of the unidentified gas.Argon is used to provide an inert blanket for certain industrial operations.An inert blanket of gas prevents any chemicals in the operation from reacting with oxygen and other substances present in air.One non-radioactive isotope is used, however, to find the age of very old rocks.
This method of dating rocks is described in the potassium entry.
If there was a new group in the periodic table, where were the other elements that belonged in the group?
Fortunately, chemists had a good idea what these missing elements might look like.
The discovery of argon created a problem for chemists. Ramsay suggested that the periodic table might have to be extended. That group would be placed to the right of Group 17 (VIIA).
Ramsay's suggestion was accepted, but it created an interesting new problem for chemists.
As the air warms, different elements change from a liquid back to a gas.