#143 Noble Gas

The six gases: helium, neon, argon, krypton, xenon and radon have a myriad of modern uses. When they were first discovered, their strangely stand-offish properties were a mystery. Uniquely stable, they [1] to participate in no chemical reactions. But by understanding the stability of the noble gases, physicists discovered the key to chemical bonding [2] . Dmitri Mendeleev added the noble gases to his periodic table in 1902, where he arranged the elements in rows and columns [3] to their atomic weight. Mendeleev was able to see repeating (or periodic) patterns in their properties. The noble gases appeared [4] in the periodic table, occurring in every eighth position, at least amongst the lighter elements.