Cadmium
transition metal · period 5 · group 12 · d-block
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury.
What the numbers say
At standard temperature and pressure Cadmium is a solid, sitting in period 5, group 12 of the d-block.
Its melting point of 594 K (321 °C) is the 78th highest of the 110 elements with a measured value — mid-range among the elements.
At 8.65 g/cm³ it is the 37th densest of 96 elements with a quoted density.
Pauling electronegativity is 1.69. Paired with oxygen (3.44) that is a difference of 1.75, which puts the bond predominantly ionic — expect a stable oxide ceramic.
In the solid state it takes a simple hexagonal structure — hexagonal packing offers few easy slip systems, so properties are anisotropic and formability is limited.
It is reported in 2 oxidation states (1, 2), which sets how many distinct compounds and phases it can form.
First identified in 1817.
Crystal structure
Solid Cadmium adopts a Simple Hexagonal arrangement, in the Hexagonal system — axes a = b ≠ c, angles α = β = 90°, γ = 120°. Symmetry controls the anisotropy of stiffness and thermal expansion, and the available slip systems set how far the metal deforms before it fractures.
Check it against computed structures
The structure search queries the Materials Project, OQMD and the Open Materials Database for computed crystal structures containing Cd — with DFT formation energy, hull stability and band gap where the provider publishes them.
K 2 · L 8 · M 18 · N 18 · O 2
Properties
| Atomic number | 48 |
|---|---|
| Atomic mass | 112.4144 u |
| Series | transition metal |
| Group | 12 |
| Period | 5 |
| Block | d-block |
| Phase at STP | Solid |
| Density | 8.65 g/cm³ |
| Melting point | 594.22 K (321 °C) |
| Boiling point | 1040 K (767 °C) |
| Electronegativity (Pauling) | 1.69 |
| Electron configuration | [Kr] 4d¹⁰ 5s² |
| Crystal structure | Simple Hexagonal |
| Oxidation states | 1,2 |
| Discovered | 1817 |
← Back to the periodic table
See Cd in context with all 118 elements.
Working with cadmium in a real design?
Ask the materials chat how Cd behaves in your alloy system, what it does to weldability, and which grades to look at — with the source of every number named.