Promethium

Properties

Atomic number

61

Atomic mass

145 u

Category

lanthanide

Group

f-block

Period

6

Block

f-block

State (room temp)

Solid

Outer-shell electrons

2

Electronegativity

1.13 (Pauling)

Density

7.26 g/cm³

Melting point

1041.85 °C

Boiling point

2999.85 °C

About Promethium

Promethium, originally prometheum, is a chemical element with the symbol Pm and atomic number 61. All of its isotopes are radioactive; it is one of only two such elements that are followed in the periodic table by elements with stable forms, a distinction shared with technetium. Chemically, promethium is a lanthanide, which forms salts when combined with other elements.

• Discovered by Chien Shiung Wu
• Named by Isotopes of promethium
• Appearance: metallic

Promethium: frequently asked questions

What is Promethium?

Promethium (Pm) is the chemical element with atomic number 61. It is a metal: specifically a lanthanide.

What is the atomic number of Promethium?

Promethium's atomic number is 61, which means every Promethium atom has 61 protons in its nucleus.

What is the electron configuration of Promethium?

The electron configuration of Promethium is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f5 (noble-gas shorthand: [Xe] 4f5 6s2). Its electrons are arranged in shells of 2, 8, 18, 23, 8, 2, with 2 in the outermost shell.

Is Promethium a metal or a nonmetal?

Promethium is a metal: specifically a lanthanide.

What group and period is Promethium in?

Promethium sits in the f-block (the lanthanide row) of period 6 on the periodic table.

Is Promethium a solid, liquid, or gas?

At room temperature, Promethium is a solid.

Position in the periodic table

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