Ionization energy, what's needed to remove 1 electron from 1 atom, is high for this non-reactive 6-element group
Sodium (symbol Na) is a soft, silvery-white, highly reactive metal and is 
a... [DOC] [TLE] Periodic table, main group elements - New World Encyclopedia [PAR] The alkali metals are the series of elements in Group 1 of the periodic table ... 
Hydrogen can form ions with a single positive charge, but removal of its single 
electron requires ...