The Noble Gases

The Noble Gases

Group 18 of long form of periodic table reported as group zero according to Mendeleef’s periodic table includes the non metallic elements Helium, Neon, Argon, Kryton and Radon. All of these are gases under ordinary conditions of temperature and pressure. All of them are present in atmosphere in minute quantities. Rn is obtained from radioactive disintegration of Ra.

On account of their very minute quantities in atmosphere, they were named as rare gases. Due to their chemical inactivity, these were prepared and thus they were named as noble gases.

Position in Periodic Table

Noble gases were not known at the time of Mandeleef and thus he did not left any place for them in his periodic table. Ramsay in 1896 suggested a new group, after the discovery of Helium and Argon, in the periodic table. Later on, other elements of this group were discovered and placed in zero group. The zero group occupies the intermediate position between the strong electronegative elements of VII A and strong electropositive elements of I A groups in periodic table and thus acts as bridge.

However, in long form of periodic table, noble gases occupy group 18 and are placed on the extreme right of the table.