Science and Technolgy.Modern alchemy.Turning a line.The race to extend the periodic table continues.ONE of the first inklings that chemistry has an underlying pattern was the discovery, early in the 19th century, of lithium, sodium and potassium-known collectively as the alkali metals.Though different from each other they have strangely similar properties.This was one of the observations that led a German chemist called Johann Debereiner to wonder if all chemical elements came in families.It took decades to tease out the truth of Debereiner's conjecture, and thus to construct the periodic table-in which the alkali metals form the first column.And it took decades more to explain why the table works (it is to do with the way electrons organise themselves in orbit around atomic nuclei).But it is a fitting tribute to Debereiner's insight that, if all goes well, some time in the next few months will bring the creation of a new alkali metal, element number 119, by his countryman Christoph Dullmann of the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt.With that addition the table will do something which has never happened before. It will grow a new row.Come in number 119.An element's atomic number is the number of protons in its nucleus.These, despite being mutually repulsive because they are positively charged, are held together by a phenomenon called the strong nuclear force.Some of this force is also supplied by neutrons, which outnumber protons in most nuclei and have no electric charge.
