Cadmium (Cd)

Cadmium properties

Atomic number

48

Atomic mass

112.41 u

Category

Transition metal

Group

12

Period

5

Block

d-block

State at room temp.

Solid

Electronegativity

1.69

Melting point

594.22 K (321.1 °C)

Boiling point

1,040 K (766.8 °C)

Density

8.65 g/cm³

Valence electrons

2

Common charges

+2

Oxidation states

+2

Atomic radius

158 pm

Ionization energy

8.994 eV

Electron affinity

—

Radioactive

No, has stable isotopes

Discovered

1817

Cadmium electron configuration

The electron configuration of Cadmium (Cd) is [Kr] 4d10 5s2. Its 48 electrons are arranged in shells as 2, 8, 18, 18, 2.

Protons, neutrons and electrons in Cadmium

A neutral Cadmium atom has 48 protons and 48 electrons. Most Cadmium atoms have about 64 neutrons: the atomic mass rounded to 112, minus the atomic number 48.

Neutrons are approximate: atoms of the same element can have different numbers of neutrons (isotopes). Atomic number and mass

How many valence electrons does Cadmium have?

2

Cadmium has 2 valence electrons, counting the electrons in its outermost s subshell. Like most transition metals, it can also use d electrons in bonding.

See every element: Periodic table with valence electrons

Cadmium orbital diagram

Each box is an orbital that holds up to two electrons with opposite spins (↑↓). The inner shells are the same as the noble gas in brackets. How to write electron configurations

Molar mass of Cadmium

112.41 g/mol

One mole of Cadmium atoms (6.022 × 10²³ atoms) has a mass of 112.41 grams. Use this value to convert between grams and moles.

Cadmium facts

• Cadmium pollution from mining waste caused itai-itai disease in Japan's Toyama Prefecture, a painful illness that softened victims' bones and damaged their kidneys.
• Cadmium's sharp red spectral line was once used as an international standard for measuring the wavelength of light.
• Cadmium (Cd) has atomic number 48 and is a solid at room temperature. It was discovered in 1817.

Position in the periodic table

Cadmium is element 48, in period 5 and group 12 of the periodic table, in the d-block.

All transition metals

Uses of Cadmium

Cadmium is used in nickel–cadmium rechargeable batteries, although these are being replaced by safer types. Cadmium telluride is the light-absorbing layer in a major type of thin-film solar panel. Cadmium compounds make bright yellow, orange, and red pigments for paints and plastics, and cadmium plating protects some aircraft steel parts from corrosion. Because cadmium is toxic, many of these uses are now restricted.

Who discovered Cadmium?

German chemist Friedrich Stromeyer discovered cadmium in 1817 in Göttingen, while investigating a sample of zinc carbonate that turned yellow when heated even though it contained no iron. He named it after cadmia, the Latin name for the zinc ore calamine.

Where does the name come from?

Cadmium comes from the Latin cadmia, from the Greek kadmeia, an old name for calamine, a zinc ore. Friedrich Stromeyer discovered the element in 1817 as an impurity in a zinc compound.

Discovery timeline