Sodium
Soft, reactive alkali metal essential for life.
Sodium is a chemical element with symbol Na (from Neo-Latin natrium) and atomic number 11. It is a soft, silvery-white, highly reactive alkali metal that does not occur free in nature and must be prepared from compounds. Sodium is the sixth-most abundant element in the Earth's crust and is essential for all animals and some plants, playing a key role in nerve impulse transmission and osmotic pressure in extracellular fluid.
- symbol
- Na
- atomic_number
- 11
- group
- 1 (alkali metal)
- stable_isotope
- 23Na
- melting_point
- 98 °C
Lore & Background
Sodium is highly reactive, combining with oxygen in air to form sodium oxides, and is typically stored in oil or inert gas. It reacts exothermically with water, producing sodium hydroxide and flammable hydrogen gas, and burns in air to form primarily sodium peroxide.
Reader's Guide
Sodium is of immense commercial importance, central to industries producing glass, paper, soap, and textiles. Key compounds include table salt (NaCl), soda ash (Na2CO3), baking soda (NaHCO3), and caustic soda (NaOH). Sodium ions are the major cation in extracellular fluid and are actively pumped out of cells by the sodium–potassium pump, enabling nerve impulse transmission via voltage-gated sodium channels. Sodium's high solubility in water means its salts are typically isolated by evaporation or precipitation with organic antisolvents. Acute neutron radiation can convert stable 23Na in human blood to radioactive 24Na, allowing radiation dosage measurement.
Did You Know?
- At high pressures, sodium changes color: at 1.5 Mbar it turns black, at 1.9 Mbar red, and at 3 Mbar it becomes a clear, transparent solid.
- Sodium forms a liquid alloy with potassium called NaK, which is an excellent thermal and electrical conductor.
Frequently Asked Questions
Who is Sodium?
Sodium is element 11, a soft silvery-white alkali metal sitting in Group 1 of the periodic table. It never appears in its bare, free form in nature and is always found locked inside compounds until it is deliberately extracted.
What are Sodium's powers or role in the story?
Its signature ability is extreme reactivity: it eagerly sheds its single outer electron to form ionic bonds and reacts violently with water. In living organisms it governs nerve-impulse transmission and maintains the osmotic pressure of extracellular fluid.
How does Sodium's story end?
In its most dramatic scene, a piece of sodium dropped into water triggers a violent exothermic reaction that releases hydrogen gas and sodium hydroxide, generating enough heat to melt the metal (melting point 98 °C). Inside the body, its arc is subtler—ion pumps constantly shuttle it across cell membranes to sustain electrical gradients.
Why is Sodium important to the wider cast?
As the sixth-most abundant element in Earth's crust, it underpins the chemistry of every animal and many plants. Without it, nerve signals could not fire and osmotic balance would collapse, making it a supporting character no storyline can do without.
Why is Sodium's symbol Na instead of S?
The symbol derives from its Neo-Latin name natrium, which itself traces back to an Arabic term for a mineral salt. That naming quirk is why the letter S on the periodic table belongs to sulfur, not sodium.
More in Chemical Elements & Metals 1-20
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record