This element is Hydrogen. Hydrogen is a nonmetal and is placed above group in the periodic table because it has ns1 electron configuration like the alkali metals. However, it varies greatly from the alkali metals as it forms cations (H+) more reluctantly than the other alkali metals. Hydrogen‘s ionization energy is 1312 kJ/mol, while lithium (the alkali metal with the highest ionization energy) has an ionization energy of 520 kJ/mol. Because hydrogen is a nonmetal and forms H- (hydride anions), it is sometimes placed above the halogens in the periodic table. Hydrogen also forms H2 dihydrogen like halogens. However, hydrogen is very different from the halogens. Hydrogen has a much smaller electron affinity than the halogens.