Sodium

Alkali metal · atomic number 11

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Sodium /ˈsoʊdiəm/ is a chemical element with symbol Na (from Ancient Greek Νάτριο) and atomic number 11. It is a soft, silver-white, highly reactive metal. In the Periodic table it is in column 1 (alkali metals), and shares with the other six elements in that column that it has a single electron in its outer shell, which it readily donates, creating a positively charged atom - a cation.

Properties of Sodium

Element category	Alkali metal
Atomic number	11
Atomic mass	22.989769282 u
Phase at STP	Solid
Group	1
Period	3
Block	s
Electron configuration	[Ne] 3s1
Electrons per shell	2, 8, 1
Electronegativity (Pauling)	0.93
Melting point	370.944 K (98 °C)
Boiling point	1156.09 K (883 °C)
Density	0.968 g/cm3
Discovered by	Humphry Davy

← Neon · Periodic table · Magnesium → Mg

About the alkali metal group

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

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

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⚛️ Full periodic table

All 118 chemical elements on one interactive, colour-coded table, each linking to a fact file and plain-language summary.

🧪 Reactive nonmetal

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

🧪 Noble gas

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.

🧪 Alkali metal

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.

🧪 Transition metal

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

🧪 Post-transition metal

9 elements: Softer, lower-melting metals beside the transition block — aluminium, tin, lead — abundant in cans, foils, solders and pigments.

🧪 Metalloid

7 elements: In-between elements that behave as semiconductors: silicon, germanium and boron underpin electronics, glass and solar cells.

🧪 Lanthanide

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

🧪 Actinide

15 elements: Mostly radioactive, heavy metals — several made only in reactors — whose fission powers nuclear energy and weapons.

🧪 Unknown properties

8 elements: Superheavy synthetic elements made atom-by-atom, existing for fractions of a second; their true chemistry is still unmeasured.