ElementsWhat are the transition metals?
The transition metals fill the wide middle block of the table, columns 3 to 12. This is where most everyday metals are found: iron, copper, zinc, nickel, silver, gold. They are usually hard and strong, with high melting points, and carry heat and electricity well. Many form coloured compounds and can combine with other elements in more than one way. Many are good catalysts, which means they speed up chemical reactions without being used up.
The family in numbers
Melting points in this family run from -38.8 °C (mercury) to 3,422 °C (tungsten). Among its solid members, the least dense is scandium (2.99 g/cm³) and the densest is osmium (22.57 g/cm³). Known since ancient times: iron, copper, silver, gold, mercury. The most recently discovered member is copernicium (1996).
What sets them apart
In the main columns of the table, an element nearly always combines in one fixed way. Transition metals are more flexible. Iron forms two series of compounds, written iron(II) and iron(III), and manganese forms several. This is because electrons from an inner shell, not only the outer one, can take part in bonding. The same inner electrons absorb light, which is why so many compounds of these metals are coloured: copper sulphate is blue, iron rust is red-brown, and compounds of chromium come in green, yellow and orange. The name chromium comes from the Greek word for colour.
Alloys
Transition metals mix well with one another and with other elements to make alloys, which are usually stronger and more useful than the pure metals. Steel is iron with a little carbon. Stainless steel adds chromium and nickel so that it does not rust. Brass is copper with zinc. Coins, tools, bridges and engines are all alloys.
Unusual members
Mercury is the only metal that is liquid at room temperature. Iron, cobalt and nickel are the three common metals that a magnet attracts. Tungsten has the highest melting point of all metals and was used for the glowing wire of light bulbs. Gold and platinum hardly react with anything, so they stay bright for centuries. The heaviest members of the block have been made only a few atoms at a time.
All transition metals compared
| No. | Symbol | Name | Atomic mass | State | Melts at | Boils at | Density g/cm³ | Discovered |
|---|---|---|---|---|---|---|---|---|
| 21 | Sc | Scandium | 44.95591 | Solid | 1,541 °C | 2,836 °C | 2.99 | 1879 |
| 22 | Ti | Titanium | 47.867 | Solid | 1,668 °C | 3,287 °C | 4.5 | 1791 |
| 23 | V | Vanadium | 50.9415 | Solid | 1,910 °C | 3,407 °C | 6 | 1801 |
| 24 | Cr | Chromium | 51.996 | Solid | 1,907 °C | 2,671 °C | 7.15 | 1797 |
| 25 | Mn | Manganese | 54.93804 | Solid | 1,246 °C | 2,061 °C | 7.3 | 1774 |
| 26 | Fe | Iron | 55.84 | Solid | 1,538 °C | 2,861 °C | 7.87 | Ancient |
| 27 | Co | Cobalt | 58.93319 | Solid | 1,495 °C | 2,927 °C | 8.86 | 1735 |
| 28 | Ni | Nickel | 58.693 | Solid | 1,455 °C | 2,913 °C | 8.91 | 1751 |
| 29 | Cu | Copper | 63.55 | Solid | 1,085 °C | 2,562 °C | 8.93 | Ancient |
| 30 | Zn | Zinc | 65.4 | Solid | 419.5 °C | 906.9 °C | 7.13 | 1746 |
| 39 | Y | Yttrium | 88.90584 | Solid | 1,522 °C | 3,345 °C | 4.47 | 1794 |
| 40 | Zr | Zirconium | 91.22 | Solid | 1,855 °C | 4,409 °C | 6.52 | 1789 |
| 41 | Nb | Niobium | 92.90637 | Solid | 2,477 °C | 4,744 °C | 8.57 | 1801 |
| 42 | Mo | Molybdenum | 95.95 | Solid | 2,623 °C | 4,639 °C | 10.2 | 1778 |
| 43 | Tc | Technetium | 96.90636 | Solid | 2,157 °C | 4,265 °C | 11 | 1937 |
| 44 | Ru | Ruthenium | 101.1 | Solid | 2,334 °C | 4,150 °C | 12.1 | 1827 |
| 45 | Rh | Rhodium | 102.9055 | Solid | 1,964 °C | 3,695 °C | 12.4 | 1803 |
| 46 | Pd | Palladium | 106.42 | Solid | 1,555 °C | 2,963 °C | 12 | 1803 |
| 47 | Ag | Silver | 107.868 | Solid | 961.8 °C | 2,162 °C | 10.5 | Ancient |
| 48 | Cd | Cadmium | 112.41 | Solid | 321.1 °C | 766.9 °C | 8.69 | 1817 |
| 72 | Hf | Hafnium | 178.49 | Solid | 2,233 °C | 4,603 °C | 13.3 | 1923 |
| 73 | Ta | Tantalum | 180.9479 | Solid | 3,017 °C | 5,458 °C | 16.4 | 1802 |
| 74 | W | Tungsten | 183.84 | Solid | 3,422 °C | 5,555 °C | 19.3 | 1783 |
| 75 | Re | Rhenium | 186.207 | Solid | 3,186 °C | 5,596 °C | 20.8 | 1925 |
| 76 | Os | Osmium | 190.2 | Solid | 3,033 °C | 5,012 °C | 22.57 | 1803 |
| 77 | Ir | Iridium | 192.22 | Solid | 2,446 °C | 4,428 °C | 22.42 | 1803 |
| 78 | Pt | Platinum | 195.08 | Solid | 1,768 °C | 3,825 °C | 21.46 | 1735 |
| 79 | Au | Gold | 196.96657 | Solid | 1,064 °C | 2,856 °C | 19.28 | Ancient |
| 80 | Hg | Mercury | 200.59 | Liquid | -38.8 °C | 356.7 °C | 13.53 | Ancient |
| 104 | Rf | Rutherfordium | 267.122 | Solid | no value | no value | no value | 1964 |
| 105 | Db | Dubnium | 268.126 | Solid | no value | no value | no value | 1967 |
| 106 | Sg | Seaborgium | 269.128 | Solid | no value | no value | no value | 1974 |
| 107 | Bh | Bohrium | 270.133 | Solid | no value | no value | no value | 1976 |
| 108 | Hs | Hassium | 269.1336 | Solid | no value | no value | no value | 1984 |
| 109 | Mt | Meitnerium | 277.154 | Solid | no value | no value | no value | 1982 |
| 110 | Ds | Darmstadtium | 282.166 | Solid | no value | no value | no value | 1994 |
| 111 | Rg | Roentgenium | 282.169 | Solid | no value | no value | no value | 1994 |
| 112 | Cn | Copernicium | 286.179 | Solid | no value | no value | no value | 1996 |
Other families: alkali metals, alkaline earth metals, post-transition metals, metalloids, nonmetals, halogens, noble gases, lanthanides, actinides.