Post-transition metal

  • post-transition metals in the periodic table
      elements classified as post-transition metals by masterton, hurley and neth:[1] ga, in, tl, sn, pb, bi
      also recognised by huheey, keiter and keiter:[2] al, ge, sb, po; and by cox:[3] zn, cd, hg
      also recognised by deming:[4] cu, ag, au (but he counted al and groups 1 and 2 as 'light metals')[n 1]
      elements that might be post-transition metals: at, cn, nh, fl, mc, lv, ts

    post-transition metals are a set of metallic elements in the periodic table located between the transition metals to their left, and the metalloids to their right. depending on where these adjacent groups are judged to begin and end, there are at least five competing proposals for which elements to include: the three most common contain six, ten and thirteen elements, respectively (see image). all proposals include gallium, indium, tin, thallium, lead, and bismuth.

    physically, post-transition metals are soft (or brittle), have poor mechanical strength, and have melting points lower than those of the transition metals. being close to the metal-nonmetal border, their crystalline structures tend to show covalent or directional bonding effects, having generally greater complexity or fewer nearest neighbours than other metallic elements.

    chemically, they are characterised—to varying degrees—by covalent bonding tendencies, acid-base amphoterism and the formation of anionic species such as aluminates, stannates, and bismuthates (in the case of aluminium, tin, and bismuth, respectively). they can also form zintl phases (half-metallic compounds formed between highly electropositive metals and moderately electronegative metals or metalloids).

    the name is universally used, but not officially sanctioned by any organization such as the iupac. the origin of the term is unclear: one early use was in 1940 in a chemistry text.[4] alternate names for this group are b-subgroup metals, other metals, and p-block metals; and at least twelve other labels.

  • applicable elements
  • rationale
  • nomenclature
  • descriptive chemistry
  • related groupings
  • notes
  • sources
  • further reading

Post-transition metals in the periodic table
  Elements classified as post-transition metals by Masterton, Hurley and Neth:[1] Ga, In, Tl, Sn, Pb, Bi
  Also recognised by Huheey, Keiter and Keiter:[2] Al, Ge, Sb, Po; and by Cox:[3] Zn, Cd, Hg
  Also recognised by Deming:[4] Cu, Ag, Au (but he counted Al and groups 1 and 2 as 'light metals')[n 1]
  Elements that might be post-transition metals: At, Cn, Nh, Fl, Mc, Lv, Ts

Post-transition metals are a set of metallic elements in the periodic table located between the transition metals to their left, and the metalloids to their right. Depending on where these adjacent groups are judged to begin and end, there are at least five competing proposals for which elements to include: the three most common contain six, ten and thirteen elements, respectively (see image). All proposals include gallium, indium, tin, thallium, lead, and bismuth.

Physically, post-transition metals are soft (or brittle), have poor mechanical strength, and have melting points lower than those of the transition metals. Being close to the metal-nonmetal border, their crystalline structures tend to show covalent or directional bonding effects, having generally greater complexity or fewer nearest neighbours than other metallic elements.

Chemically, they are characterised—to varying degrees—by covalent bonding tendencies, acid-base amphoterism and the formation of anionic species such as aluminates, stannates, and bismuthates (in the case of aluminium, tin, and bismuth, respectively). They can also form Zintl phases (half-metallic compounds formed between highly electropositive metals and moderately electronegative metals or metalloids).

The name is universally used, but not officially sanctioned by any organization such as the IUPAC. The origin of the term is unclear: one early use was in 1940 in a chemistry text.[4] Alternate names for this group are B-subgroup metals, other metals, and p-block metals; and at least twelve other labels.