ElementsWhat are the post-transition metals?
The post-transition metals sit to the right of the transition metals. They are softer and melt at lower temperatures than most transition metals. Aluminium, tin and lead are the best known. The heaviest members shown here, from nihonium to livermorium, have been made only a few atoms at a time, so their place in this family is a prediction.
The family in numbers
Melting points in this family run from 29.8 °C (gallium) to 660.3 °C (aluminium). Among its solid members, the least dense is aluminium (2.7 g/cm³) and the densest is thallium (11.8 g/cm³). Known since ancient times: tin, lead. The most recently discovered member is nihonium (2004).
What they are like
These metals are softer and weaker than the transition metals beside them, and most melt easily. Tin and lead can be melted on a kitchen stove. Gallium melts at about 30 °C, so a piece of it turns liquid in a warm hand. They conduct electricity, but less well than copper or silver. Chemically they are less eager to react than the metals on the left of the table.
Where you meet them
Aluminium is the most abundant metal in the Earth's crust and one of the most used: in drink cans, foil, window frames, aircraft and power lines. It is reactive, but a thin, tough layer of oxide forms on its surface and protects the metal underneath, so it does not rust away as iron does. Tin coats steel food cans to keep them from rusting, and with lead it made the traditional solder for joining wires. Lead is very dense and stops X-rays, and it is still used in car batteries. Indium, in a clear compound that conducts electricity, makes touch screens work. Bismuth compounds are used in some stomach medicines.
A warning
Lead and thallium are poisons that build up in the body. Lead has been removed from petrol, paint and water pipes in most countries for that reason.
All post-transition metals compared
| No. | Symbol | Name | Atomic mass | State | Melts at | Boils at | Density g/cm³ | Discovered |
|---|---|---|---|---|---|---|---|---|
| 13 | Al | Aluminium | 26.981538 | Solid | 660.3 °C | 2,519 °C | 2.7 | 1825 |
| 31 | Ga | Gallium | 69.723 | Solid | 29.8 °C | 2,204 °C | 5.91 | 1875 |
| 49 | In | Indium | 114.818 | Solid | 156.6 °C | 2,072 °C | 7.31 | 1863 |
| 50 | Sn | Tin | 118.71 | Solid | 231.9 °C | 2,602 °C | 7.29 | Ancient |
| 81 | Tl | Thallium | 204.383 | Solid | 303.9 °C | 1,473 °C | 11.8 | 1861 |
| 82 | Pb | Lead | 207 | Solid | 327.5 °C | 1,749 °C | 11.34 | Ancient |
| 83 | Bi | Bismuth | 208.98040 | Solid | 271.4 °C | 1,564 °C | 9.81 | 1753 |
| 113 | Nh | Nihonium | 286.182 | Solid | no value | no value | no value | 2004 |
| 114 | Fl | Flerovium | 290.192 | Solid | no value | no value | no value | 1998 |
| 115 | Mc | Moscovium | 290.196 | Solid | no value | no value | no value | 2003 |
| 116 | Lv | Livermorium | 293.205 | Solid | no value | no value | no value | 2000 |
Other families: alkali metals, alkaline earth metals, transition metals, metalloids, nonmetals, halogens, noble gases, lanthanides, actinides.