Cadmium (Cd)
Element 48 · Transition metal · Solid at 25 °C · Group 12, Period 5
Cadmium powered generations of rechargeable NiCd batteries and colored artists' yellows — uses now restricted because the metal is toxic.
On the periodic table, cadmium sits in group 12 in period 5. It is one of 38 elements classified as a transition metal, and at room temperature (25 °C) it is a solid.
Transition metals occupy the wide d-block in the middle of the table. As a family they are hard, dense, high-melting metals that conduct heat and electricity well. Their partly filled d-orbitals let many of them take several oxidation states, form vividly colored compounds, and act as catalysts — which is why so much of industry, and so much of biology, runs on this block.
Properties of cadmium
| Atomic number (Z) | 48 |
|---|---|
| Symbol | Cd |
| Atomic mass | 112.41 |
| Category | Transition metal |
| Group | 12 |
| Period | 5 |
| Block | d-block |
| Metal / nonmetal | Metal |
| State at 25 °C | Solid |
| Electron configuration | [Kr] 4d10 5s2 |
| Electronegativity (Pauling) | 1.69 |
| Melting point | 321.07 °C (594.22 K / 609.93 °F) |
| Boiling point | 767 °C (1,040.15 K / 1,412.6 °F) |
| Density | 8.65 g/cm³ |
Position in the periodic table
Cadmium shares group 12 with Zinc (Zn), Mercury (Hg), Copernicium (Cn). Elements in the same group have the same number of outer electrons, so they tend to behave alike chemically — comparing them is one of the fastest ways to see periodic trends in action.
Physical properties
Cadmium melts at 321.07 °C (594.22 K / 609.93 °F) and boils at 767 °C (1,040.15 K / 1,412.6 °F), giving it a liquid range of about 445.9 °C at standard pressure.
Its density is 8.65 g/cm³.
See also: the interactive periodic table, how to read the periodic table, periodic trends.