Barium

Alkaline earth metal · atomic number 56

56137.3277BaBariumSolidAlkaline earth metal

Barium is a chemical element with symbol Ba and atomic number 56. It is the fifth element in Group 2, a soft silvery metallic alkaline earth metal. Because of its high chemical reactivity barium is never found in nature as a free element.

Properties of Barium

Element category	Alkaline earth metal
Atomic number	56
Atomic mass	137.3277 u
Phase at STP	Solid
Group	2
Period	6
Block	s
Electron configuration	[Xe] 6s2
Electrons per shell	2, 8, 18, 18, 8, 2
Electronegativity (Pauling)	0.89
Melting point	1000 K (727 °C)
Boiling point	2118 K (1845 °C)
Density	3.51 g/cm3
Discovered by	Carl Wilhelm Scheele

← Cesium · Periodic table · Lanthanum → La

About the alkaline earth metal group

Reactive group-2 metals a step calmer than the alkalis: magnesium, calcium and the structural and biological workhorses among them.

Data: Periodic-Table-JSON (CC BY-SA 3.0) · stored statically on our server. https://en.wikipedia.org/wiki/Barium

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🧪 Reactive nonmetal

11 elements: Elements that readily gain or share electrons — the building blocks of water, air, living tissue and most organic chemistry.

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6 elements: Full outer electron shells make these gases almost inert: they barely react, glow in discharge lamps and are used to create unreactive atmospheres.

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6 elements: Soft, wildly reactive metals of group 1 — they fizz in water and never occur pure in nature. Lithium, sodium, potassium and friends.

🧪 Alkaline earth metal

6 elements: Reactive group-2 metals a step calmer than the alkalis: magnesium, calcium and the structural and biological workhorses among them.

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35 elements: The dense, strong, catalytic heart of the table — iron, copper, gold, titanium — responsible for most of metallurgy, jewellery and industry.

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15 elements: The rare-earth “inner transition” metals that give strong permanent magnets, screen phosphors and catalyst polish.

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