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Promethium (Pm) – Element 61 of the periodic table

Promethium (symbol Pm) is element number 61 of the periodic table and belongs to the “Lanthanide” category. Its atomic mass is about 145, and its phase under standard conditions is Solid. This element sits in period 6 and the f-block (Lanthanides) of the periodic table, and its electrons are arranged in shells of 2, 8, 18, 23, 8, 2. The short electron configuration of Promethium is [Xe] 4f⁵ 6s². Known uses of Promethium include Atomic batteries, Luminous paints and Scientific research.

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Properties of Promethium

Atomic number
61
Chemical symbol
Pm
Atomic mass
145
Category
Lanthanide
Period
6
Block
f
Phase
Solid
Protons
61
Electrons
61
Neutrons (approx.)
84
Electron shells
2, 8, 18, 23, 8, 2
Outer-shell electrons
2
Discovered
Jacob A. Marinsky (1945)

Electron configuration of Promethium

The electron configuration of Promethium (Pm), with 61 electrons, is shown below. The last shell (shell 6) is highlighted:

Full configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f⁵ 5s² 5p⁶ 6s²
Short configuration
[Xe] 4f⁵ 6s²
Last shell
6s²

What is electron configuration and how is it written?

Electron shells of Promethium

Distribution of 61 electrons of Promethium across shells K to P:

  1. K2
  2. L8
  3. M18
  4. N23
  5. O8
  6. P2

What is a lanthanide?

The lanthanides are the 15 elements from lanthanum to lutetium, part of the f-block, with very similar chemical properties; they are often grouped among the “rare earths”.

Uses of Promethium

Frequently asked questions about Promethium

What is the atomic number of Promethium?

The atomic number of Promethium (Pm) is 61; that is, every atom of it has 61 protons.

What is the electron configuration of Promethium?

The electron configuration of Promethium (Pm) is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f⁵ 5s² 5p⁶ 6s²; in short form it is [Xe] 4f⁵ 6s², and its last shell is 6s².

What is the chemical symbol of Promethium?

The chemical symbol of Promethium is Pm.

Where is Promethium located in the periodic table?

Promethium is located in period 6 and the f-block (Lanthanides) and belongs to the “Lanthanide” category.

What is the atomic mass of Promethium?

The atomic mass of Promethium is about 145 (atomic mass units).

What is the phase of Promethium under normal conditions?

The phase of Promethium under standard conditions is Solid.

What are the uses of Promethium?

Uses of Promethium include Atomic batteries, Luminous paints and Scientific research.

Who discovered Promethium?

Promethium was discovered by Jacob A. Marinsky in 1945.

Elements in the same category as Promethium (Lanthanide)

Lanthanum (La)Cerium (Ce)Praseodymium (Pr)Neodymium (Nd)Samarium (Sm)Europium (Eu)Gadolinium (Gd)Terbium (Tb)Dysprosium (Dy)Holmium (Ho)Erbium (Er)Thulium (Tm)Ytterbium (Yb)Lutetium (Lu)

See all Lanthanides