48112.41CdCadmium
Cadmium (Cd) — element 48transition metal · group 12, period 5
Cadmium is a chemical element with the symbol Cd and atomic number 48. It is a transition metal in group 12, period 5 of the periodic table (the d-block), with a standard atomic mass of 112.41 u. At room temperature (25 °C) cadmium is a solid.
💡 Known for: Used in nickel–cadmium batteries and pigments; it is toxic, so its use is now restricted.
# Cadmium properties
| Symbol | Cd |
|---|---|
| Atomic number | 48 |
| Atomic mass | 112.41 u |
| Category | transition metal |
| Group | 12 |
| Period | 5 |
| Block | d-block |
| Electron configuration | [Kr] 4d¹⁰ 5s² |
| Full configuration | 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² |
| Electrons per shell | 2, 8, 18, 18, 2 |
| Protons / electrons | 48 / 48 |
| State at 25 °C | solid |
| Melting point | 594.22 K (321.1 °C, 609.9 °F) |
| Boiling point | 1040 K (766.9 °C, 1412.3 °F) |
| Density | 8.69 g/cm³ |
| Electronegativity (Pauling) | 1.69 |
| First ionization energy | 8.994 eV |
| Atomic radius | 161 pm |
| Discovered | 1817 |
# Electron configuration of cadmium
The electron configuration of cadmium is [Kr] 4d¹⁰ 5s², written out in full as 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s². Its 48 electrons fill 5 shells as 2, 8, 18, 18, 2, so the outermost shell holds 2 electrons.
# Related elements
AgSilverprevious elementInIndiumnext elementZnZincgroup 12HgMercurygroup 12CnCoperniciumgroup 12ScScandiumtransition metalTiTitaniumtransition metalVVanadiumtransition metalCrChromiumtransition metalMnManganesetransition metalFeIrontransition metalCoCobalttransition metalNiNickeltransition metal
# Cadmium FAQ
What is the atomic number of cadmium?
The atomic number of cadmium is 48: every cadmium atom has 48 protons in its nucleus. Its symbol is Cd.
What is the atomic mass of cadmium?
The standard atomic mass of cadmium is 112.41 u.
What is the electron configuration of cadmium?
Cadmium's electron configuration is [Kr] 4d¹⁰ 5s² (1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s²), with 2, 8, 18, 18, 2 electrons per shell.
Is cadmium a metal?
Yes. Cadmium is a transition metal, one of the metals.
What is the melting point of cadmium?
Cadmium melts at 594.22 K (321.1 °C, 609.9 °F) and boils at 1040 K (766.9 °C, 1412.3 °F).
What is cadmium used for / known for?
Used in nickel–cadmium batteries and pigments; it is toxic, so its use is now restricted.