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Radium (Ra) – Element 88 of the periodic table

Radium (symbol Ra) is element number 88 of the periodic table and belongs to the “Alkaline earth metal” category. Its atomic mass is about 226, and its phase under standard conditions is Solid. This element sits in period 7 and group 2 of the periodic table, and its electrons are arranged in shells of 2, 8, 18, 32, 18, 8, 2. The short electron configuration of Radium is [Rn] 7s². Known uses of Radium include Cancer treatment, Luminous paints and Scientific research.

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Properties of Radium

Atomic number
88
Chemical symbol
Ra
Atomic mass
226
Category
Alkaline earth metal
Period
7
Group
2
Phase
Solid
Protons
88
Electrons
88
Neutrons (approx.)
138
Electron shells
2, 8, 18, 32, 18, 8, 2
Outer-shell electrons
2
Discovered
Marie Curie (1898)

Electron configuration of Radium

The electron configuration of Radium (Ra), with 88 electrons, is shown below. The last shell (shell 7) is highlighted:

Full configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 7s²
Short configuration
[Rn] 7s²
Last shell
7s²

What is electron configuration and how is it written?

Electron shells of Radium

Distribution of 88 electrons of Radium across shells K to Q:

  1. K2
  2. L8
  3. M18
  4. N32
  5. O18
  6. P8
  7. Q2

What is a alkaline earth metal?

The alkaline earth metals are the group 2 elements: reactive metals, harder than the alkali metals and with higher melting points, that usually form ions with a +2 charge.

Uses of Radium

Frequently asked questions about Radium

What is the atomic number of Radium?

The atomic number of Radium (Ra) is 88; that is, every atom of it has 88 protons.

What is the electron configuration of Radium?

The electron configuration of Radium (Ra) is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 7s²; in short form it is [Rn] 7s², and its last shell is 7s².

What is the chemical symbol of Radium?

The chemical symbol of Radium is Ra.

Where is Radium located in the periodic table?

Radium is located in period 7 and group 2 and belongs to the “Alkaline earth metal” category.

What is the atomic mass of Radium?

The atomic mass of Radium is about 226 (atomic mass units).

What is the phase of Radium under normal conditions?

The phase of Radium under standard conditions is Solid.

What are the uses of Radium?

Uses of Radium include Cancer treatment, Luminous paints and Scientific research.

Who discovered Radium?

Radium was discovered by Marie Curie in 1898.

Elements in the same category as Radium (Alkaline earth metal)

Beryllium (Be)Magnesium (Mg)Calcium (Ca)Strontium (Sr)Barium (Ba)

See all Alkaline earth metals

Radium’s group 2 neighbours

Beryllium (Be)Magnesium (Mg)Calcium (Ca)Strontium (Sr)Barium (Ba)

Group 2 of the periodic table