How do you rank metallic character?

1 Answer
Dec 28, 2016

Usually by electronegativity, i.e. the ability to attract electron density towards oneself. For example:

  • Metallic character tends to increase downwards, since the lower halogens are less electronegative than the ones closer to #"F"#.

That is reflected in that:

  • #"F"# is a gas (#T_(bp) = -188.1^@ "C"#),
  • #"Cl"# is a denser gas (#"3.2 g/L"# vs. #"1.696 g/L"#),
  • #"Br"# is a liquid (#T_(mp) = -7^@ "C"#, #T_(bp) = 58.8^@ "C"#),
  • #"I"# is a solid (#T_(mp) = 113.7^@ "C"#),
  • and #"At"# is denser than #"I"# (formally a nonmetal, but denser than a solid!).
  • Metallic character tends to increase leftwards, since electronegativity tends to decrease leftwards on the periodic table.

Hence, #"Li"# is more of a metal than #"N"#, which is obvious, because #"N"_2# is a gas in natural conditions, and #"Li"# is literally of the "alkali metal" class.

Overall, it therefore means that metallic character has a general trend towards the lower left of the periodic table (with some exceptions in the transition metals of course).