Where does potassium get K from? Unraveling the Element's Latin Roots

December 29, 2025 •

3 min read

The chemical symbol for potassium is K, an apparent inconsistency on the periodic table that has a rich linguistic history. The answer to where does potassium get K from involves a journey back to the element's Latin name, kalium, and a historical naming debate that took place in the early 19th century.

Quick Summary

Potassium's symbol, K, originates from the Latin term kalium, a name proposed by Swedish chemist Jöns Jacob Berzelius. The Latin term traces its roots to the Arabic word for 'plant ashes,' reflecting the historical method of obtaining its salts.

Key Points

Symbol Origin: The symbol 'K' for potassium comes from the Latin name kalium, not the English 'potassium'.
Arabic Root: The Latin kalium has its own history, originating from the Arabic word al-qaliyah, which refers to 'plant ashes'.
Historical Discovery: British chemist Sir Humphry Davy first isolated the element in 1807 and named it potassium, from which potash (pot ashes) was derived.
Symbol Standardized: The symbol K was proposed by Swedish chemist Jöns Jacob Berzelius and was eventually adopted as the international standard.
Essential Electrolyte: In the human body, potassium is a vital electrolyte that regulates fluid balance, nerve signals, and muscle contractions, including heartbeat.
Dietary Importance: A diet rich in potassium, found in fruits, vegetables, and legumes, helps regulate blood pressure by counteracting the effects of sodium.

The Linguistic Origin of 'K'

At first glance, the chemical symbol 'K' for potassium seems out of place on the periodic table. While many elements have symbols that align with their modern English names (e.g., 'H' for Hydrogen, 'O' for Oxygen, 'Ca' for Calcium), potassium does not. The reason is that its symbol is derived from its Latin name, kalium.

The Arabic and Latin Connection

The story begins with the term alkali, which comes from the Arabic word al-qaliyah, meaning 'the ashes'. In medieval times, alkalis were obtained from the ashes of burnt plants, a compound known in English as 'potash' or 'pot ashes'. The Latin name kalium was adopted to reflect this heritage. The International Union of Pure and Applied Chemistry (IUPAC) later standardized the symbol K, based on the Latin name, ensuring consistency across different languages.

The Great Naming Convention Debate

In 1807, the British chemist Sir Humphry Davy was the first to isolate pure potassium metal through the electrolysis of molten potash. Following his discovery, he named the element 'potassium,' a name derived from the English word 'potash'. However, another prominent chemist, the Swede Jöns Jacob Berzelius, proposed an alternative. Berzelius was instrumental in developing the modern system of chemical symbols and, in 1814, advocated for the name kalium and the symbol K.

This led to a split in naming conventions. While English and French-speaking nations adopted Davy's 'potassium,' the Germanic countries and others adopted Berzelius's 'kalium'. Ultimately, Berzelius's systematic approach prevailed in the periodic table's symbolic representation, though the English name persisted.

What is Potassium and Why is It Important?

Potassium (atomic number 19) is a soft, silvery-white alkali metal. It is highly reactive and readily tarnishes when exposed to air, meaning it is never found in its pure metallic form in nature. Instead, it exists in compounds and is the seventh most abundant element in the Earth's crust, found in minerals like sylvite and carnallite. Potassium is an essential mineral for both plant and animal life.

In the human body, potassium acts as a crucial electrolyte, a mineral that carries an electric charge and is vital for many physiological processes.

Essential Functions of Potassium

Fluid Balance: It helps maintain the correct balance of fluids, ensuring cells have enough water to function properly.
Nerve Function: Potassium ions are necessary for normal nerve transmission, enabling communication throughout the nervous system.
Muscle Contraction: It plays a vital role in muscle contractions, including the regular beating of the heart.
Blood Pressure Regulation: A diet rich in potassium can help regulate blood pressure by offsetting the harmful effects of high sodium intake.

Dietary Sources of Potassium

Getting enough potassium from your diet is essential. Here are some of the best food sources:

Fruits: Bananas, oranges, cantaloupe, dried apricots, raisins, and prunes.
Vegetables: Potatoes, sweet potatoes, spinach, broccoli, and tomatoes.
Legumes: Lentils, kidney beans, and soybeans.
Dairy: Milk and yogurt.
Fish: Salmon and tuna.

Comparison of Electrolytes: Potassium vs. Sodium

Potassium and sodium are both crucial electrolytes, but they play opposite roles within the body's cells. This table highlights their key differences.


Feature	Potassium (K)	Sodium (Na)
Primary Location	Predominantly inside cells (intracellular).	Predominantly outside cells (extracellular).
Fluid Regulation	Holds water inside cells.	Holds water outside cells.
Blood Pressure Effect	Helps lower blood pressure by helping the kidneys excrete excess sodium.	Excess intake can lead to higher blood pressure.
Dietary Source	Found widely in fruits, vegetables, and legumes.	Primarily comes from processed foods and table salt.
Abundance	Most people consume less than the recommended amount.	Most people consume more than the recommended amount.

Conclusion: The Persistence of a Name

The story of where does potassium get K from is a perfect illustration of how modern scientific terminology can be influenced by historical language and events. While Humphry Davy's 'potassium' prevailed in common English, the Latin-derived symbol K, championed by Berzelius, became the universal standard for the element. This dual identity—a Latin symbol for an English name—serves as a constant reminder of the evolution of chemistry and language. By understanding this backstory, we gain a richer appreciation for the periodic table and the scientific debates that shaped it. For further reading on the fascinating history of the periodic table, explore the Royal Society of Chemistry's excellent resource: https://periodic-table.rsc.org/element/19/potassium.

Frequently Asked Questions

The symbol 'P' is used for the element phosphorus. Potassium's symbol, K, was adopted from its Latin name, kalium, which was proposed by Swedish chemist Jöns Jacob Berzelius during the development of chemical nomenclature.

The Latin name kalium is derived from the Arabic word al-qaliyah, which translates to 'plant ashes'. This name reflects the historical method of obtaining potassium salts, or potash, from burnt plant matter.

Yes, the English name 'potassium' was coined by Sir Humphry Davy in 1807 when he isolated the element. He named it after 'potash,' the compound from which he extracted it.

Potassium is an essential electrolyte that helps maintain fluid balance within the body's cells. It is also crucial for proper nerve function, muscle contractions, and regulating blood pressure.

Many fruits, vegetables, and legumes are excellent sources. These include potatoes, bananas, spinach, dried apricots, beans, milk, and yogurt.

Potassium and sodium work together as electrolytes but have opposing effects. Potassium helps flush excess sodium from the body and draws water into cells, while sodium attracts water outside of cells. A healthy balance is critical for regulating blood pressure.

Yes. Low potassium (hypokalemia) and high potassium (hyperkalemia) can both be serious health concerns. Severe cases of either can cause heart problems, muscle weakness, and other health issues, so it's important to consult a doctor if you suspect an imbalance.