K
39.098Potassium
Potasyum
Potassium is a soft, reactive alkali metal with atomic number 19. Potassium ions are essential for nerve signals, muscle function and fluid balance, while potassium compounds are widely used in fertilizers, glass, soaps and medicine.
19
39.098 g/mol
[Ar] 4s¹
2 | 8 | 8 | 1
0.82
0.862 g/cm³
63.38 °C
758.9 °C
Humphry Davy
Potassium was isolated by Humphry Davy in 1807 through electrolysis of potash. The English name comes from potash, while the symbol K comes from kalium, a Latinized name linked to alkali.
Potassium-39
Natural abundance: About 93.3%. The most abundant stable isotope of potassium.Potassium-40
Natural abundance: About 0.012%. Half-life: About 1.25 billion years. Naturally radioactive isotope used in potassium-argon dating.Potassium-41
Natural abundance: About 6.7%. Stable isotope of potassium.KCl
Potassium ChlorideUsed in fertilizers, medicine and salt substitutes.KOH
Potassium HydroxideStrong base used in soaps, detergents and alkaline batteries.KNO₃
Potassium NitrateUsed in fertilizers, black powder and some food-preservation applications.K₂CO₃
Potassium CarbonateUsed in glass, soaps and chemical manufacturing.KMnO₄
Potassium PermanganateStrong oxidizing agent used in chemistry and water treatment.- Potassium fertilizers for plant growth
- Potassium nitrate in fertilizers, food preservation and black powder formulations
- Potassium carbonate in glass manufacturing
- Potassium hydroxide in liquid soaps, detergents and alkaline batteries
- Potassium chloride in medicine, electrolyte solutions and salt substitutes
- Potassium compounds in chemical synthesis and industrial processes
Potassium is essential for life as K⁺ ions. It helps regulate fluid balance, nerve impulses, muscle contraction and heart rhythm, and it is a major electrolyte inside cells.
- Potassium metal is soft enough to cut with a knife and tarnishes quickly in air.
- Potassium is less dense than sodium, an exception to the simple “density increases down the alkali metals” idea.
- Potassium gives a lilac flame color in flame tests.
- The radioactive isotope potassium-40 contributes a small part of natural background radiation and decays to both argon-40 and calcium-40.
- Potassium has atomic number 19 and belongs to group 1, the alkali metals.
- Its electron configuration is [Ar] 4s¹.
- Potassium commonly forms K⁺ by losing one valence electron.
- The sodium-potassium pump moves Na⁺ and K⁺ ions across cell membranes and is essential for nerve and muscle function.
What is the atomic number of potassium?
The atomic number of potassium is 19.
What is the electron configuration of potassium?
Potassium has the electron configuration [Ar] 4s¹.
Why is the symbol for potassium K?
The symbol K comes from kalium, a Latinized name related to alkali.
What color is potassium in a flame test?
Potassium gives a lilac or pale purple flame color, often easier to see through cobalt glass.
Why is potassium important in the body?
Potassium ions help maintain membrane potential, nerve signaling, muscle contraction and heart rhythm.
What is potassium used for?
Potassium compounds are used in fertilizers, glass, soaps, detergents, medicine, electrolyte solutions and chemical manufacturing.