Cadmium (Cd)

Cadmium is a transition metal with atomic number 48, in period 5 and group 12 of the periodic table. Its atomic mass is 112.414 u and its electron configuration is [Kr] 4d¹⁰ 5s². Solid at 25 °C.

Download on theApp Store

Key facts

Atomic number	48
Atomic mass	112.414 u
Category	Transition Metal
Period	5
Group	12
Block	d
Electron configuration	[Kr] 4d¹⁰ 5s²
Electrons per shell	2, 8, 18, 18, 2
Electronegativity (Pauling)	1.69
Oxidation states	−2, +1, +2common in bold
State at 25 °C	Solid
Melting point	594.22 K321.07 °C
Boiling point	1040 K766.85 °C
Density	8.65 g/cm³

Atomic properties

First ionization energy	8.994 eV
Electron affinity	0 kJ/mol
Atomic radius	154 pm
Covalent radius	144 pm
Van der Waals radius	158 pm
Common ions	Cd²⁺
Protons, neutrons, electrons	48, 64, 48

Physical and thermal properties

Molar volume	13 cm³/mol
Heat of fusion	6.3 kJ/mol
Heat of vaporization	100 kJ/mol
Specific heat	230 J/(kg·K)
Thermal conductivity	96 W/(m·K)
Thermal expansion	3.08 × 10⁻⁵ K⁻¹
Mohs hardness	2
Young’s modulus	50 GPa
Crystal structure	Simple hexagonal
Magnetic type	Diamagnetic

Identification and history

CAS number	7440-43-9
Latin name	Cadmium
Discovered by	K. Leberecht, F. Stromeyer · 1817
Named by	Friedrich Stromeyer · 1817

Natural isotopes

Isotope	Mass (u)	Abundance
¹⁰⁶Cd	105.90646	1.245 %
¹⁰⁸Cd	107.904184	0.888 %
¹¹⁰Cd	109.903007	12.47 %
¹¹¹Cd	110.904184	12.795 %
¹¹²Cd	111.902764	24.109 %
¹¹³Cd	112.904408	12.227 %
¹¹⁴Cd	113.903365	28.754 %
¹¹⁶Cd	115.904763	7.512 %

Data checked against PubChem (NIH), IUPAC, the NIST Atomic Spectra Database and the IAEA (NUBASE and AME), the same data you see in the app.

A dash (---) means there is no reliable published measurement. The app never makes one up.

See Cadmium in the app

Orbital diagram with Hund’s rule, emission spectrum, shell model, every isotope, a real photo, and comparison with any other element. Free, no ads, works offline.

Download on theApp Store