(Jimmy of the Clue Crew indicates the right-hand column of the periodic table.) On the periodic table, the six gases in this column, beginning with helium & ending with radon, are described as this, because they don't readily react with other elements
depending on the ..... 
Atmsfera  Earth's atmospheric gases scatter blue light more than other 
wavelengths, ...... Tabla peridica de los elementos  The periodic table is a 
tabular ... trends, such as elements with similar behaviour in the same column.