Element identity
Atomic number, symbol, relative atomic mass display and periodic position are established reference data.
Atomic / electronic model
Ground-state electron configuration and atomic reference values are compiled/evaluated data; orbital graphics are teaching probability models, not photographs.
Material / molecular structure
The displayed ordinary structure is based on established material or molecular science; simplified viewers are labelled as teaching schematics where exact crystallographic coordinates are not rendered.
Temperature / phase path
Transition values are reference/evaluated values for the stated teaching path; pressure, purity and allotropy can matter.
Geography
Real pins use reviewed place/dataset context. Conceptual layers are used when country pins would imply false occurrence, unsafe inventory or an incomplete global distribution.
The lens describes evidence status, not confidence theatre. “Unknown” is kept unknown, and teaching schematics are not presented as direct measurements.
Potassium (K)
Potassium is a soft Group 1 alkali metal whose single 4s valence electron explains the strong tendency to form K⁺. In nature it occurs in compounds, while potassium ions are essential in cells and potassium salts are central to fertilizers.
Potassium atomic number, mass, electron configuration and key properties
Potassium: quick answers
How many protons, neutrons and electrons does potassium have?
Potassium’s atomic number is 19, so every potassium atom has 19 protons, and a neutral atom also has 19 electrons. Its most common natural isotope, potassium-39, has 20 neutrons (other isotopes have different neutron counts).
What is the symbol for potassium?
The chemical symbol for potassium is K.
Is potassium a solid, liquid or gas at room temperature?
Potassium is a solid at room temperature (about 25 °C).
What family (group) is potassium in?
Potassium is an alkali metal, in group 1, period 4 of the periodic table.
How many valence electrons does potassium have?
Potassium has 1 valence electron, the single electron in its outer shell, which matches its position in group 1.
What is the electron configuration of potassium?
The ground-state electron configuration of potassium is [Ar] 4s¹.
From atomic number to chemistry
Read these as a chain of causes, not as isolated facts. Each step links to the concept hub if you want the underlying idea explained.
Nineteen protons define potassium; neutral K also has 19 electrons.
The single outer 4s electron is the key starting point for alkali-metal chemistry.
Losing that outer electron gives the familiar K+ ion.
Potassium continues the alkali-metal pattern below sodium.
Natural potassium mixes stable and radioactive isotopes without changing the element identity.
Potassium in its period and family
Potassium begins Period 4 in Group 1, directly below sodium. Its [Ar] 4s¹ configuration continues the alkali-metal pattern: one outer s electron, low first ionization energy and strong +1 chemistry.
Potassium Visual Lab
Decode potassium’s tile, compare neutral K with K⁺ electron counts, rotate a ³⁹K teaching nucleus and BCC metal cell, inspect 4s/3p probability models, and connect potassium to cells, fertilizers and potash geography.
Every mark points to one exact feature
The numbered markers explain the same information system used throughout Element Lookup. Unknown or predicted fields remain visibly labelled rather than being replaced with guesses.
Potassium in one minute
Atomic number 19 means every potassium nucleus contains 19 protons.
Neutral potassium has one outer 4s electron and commonly forms K⁺ by losing it.
³⁹K is the most abundant natural potassium isotope; ⁴⁰K is a naturally occurring radioactive isotope.
Potassium metal is body-centred cubic near room temperature.
Most commercial “potash” statistics describe potassium-bearing fertilizer commodities, commonly reported as K₂O equivalent - not elemental potassium metal.
Shell rings organize electron counts. They are not electron trajectories or orbital shapes.
2 · 8 · 8 · 1 electrons
The 4s view represents the occupied valence orbital and includes three radial nodes in a hydrogen-like teaching approximation. The 3p view represents an occupied core subshell with one radial node and selectable p orientation. These are probability models, not electron paths.
Body-centred cubic potassium metal near room temperature (Im-3m teaching cell). The viewer is evidence-aware: measured structures are identified as such; unknown bulk structures stay unknown.
Teaching visualization; not a literal finite sample or thermal trajectory.What this model does—and does not—show
The 4s view represents the occupied valence orbital and includes three radial nodes in a hydrogen-like teaching approximation. The 3p view represents an occupied core subshell with one radial node and selectable p orientation. These are probability models, not electron paths.
Where do I meet potassium?
Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.
Fertilizers
Potassium compounds are one of the three major fertilizer nutrient families; potash commodities replenish potassium removed from agricultural soils.
Potassium atom, K+ ion and potash are different objects
Searches often mix elemental potassium, biological K+ and potash commodities. This switcher keeps them separate.
Neutral potassium
A neutral potassium atom has one 4s electron outside an argon-like core.
Sodium, potassium and rubidium
Group 1 keeps one outer s electron while atomic size generally increases down the column. Potassium continues the alkali-metal pattern but should still be treated as its own measured element.
| Valence | 3s¹ |
|---|---|
| State | soft reactive metal |
| Valence | 4s¹ |
|---|---|
| Common ion | K⁺ |
| Crystal | BCC |
| Valence | 5s¹ |
|---|---|
| Context | heavier alkali metal |
Potassium properties: atomic, physical, thermal and chemical
Categories follow the science of this element rather than a fixed decorative template. Each row carries condition/provenance context and an evidence label; unknown values stay unknown.
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Atomic number | 19 | Source-reviewed; see Sources below | Evaluated |
| Relative atomic mass | 39.0983 | Source-reviewed; see Sources below | Evaluated |
| Ground-state electron configuration | [Ar] 4s¹ | Source-reviewed; see Sources below | Evaluated |
| Group / period / block | Group 1 · Period 4 · s-block | Periodic-table placement | Evaluated |
| Electronegativity | 0.82 | Source-reviewed; see Sources below | Evaluated |
| Reference isotope | ³⁹K | Source-reviewed; see Sources below | Evaluated |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| State context | Solid metal at 20 °C | Source-reviewed; see Sources below | Evaluated |
| Density | 0.89 g/cm³ | Source-reviewed; see Sources below | Evaluated |
| Material / molecular structure | BCC | Body-centred cubic potassium metal near room temperature (Im-3m teaching cell) | Measured |
| Classification | Alkali metal | Periodic-table / chemistry classification | Evaluated |
| Structure-model scope | Body-centred cubic potassium metal near room temperature (Im-3m teaching cell) | Teaching visualization; exact crystallographic coordinates are not implied unless stated. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Melting / transition reference | 336.7 K | Source-reviewed; see Sources below | Evaluated |
| Boiling / gas reference | 1032 K | Source-reviewed; see Sources below | Evaluated |
| Phase-path context | On this approximately standard-pressure teaching path, potassium is solid below 336.7 K, liquid between 336.7 K and 1032 K, and gaseous above 1032 K. | Shared phase registry drives the slider, regions and markers. | Evaluated |
| Condition warning | Temperature and pressure define phase behavior; purity/allotropy may matter. | Teaching condition statement | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Ordinary electrical behavior | Metallic conductor | Qualitative bulk behavior; exact resistivity depends on temperature, purity and alloy state. | Measured |
| Conduction model | Collective solid-state electrons | Do not interpret isolated-atom orbital clouds as literal current paths. | Reviewed |
| Surface / compound caveat | Oxides, salts and alloys can behave differently from the pure metal | Material context | Reviewed |
| Engineering values | Condition-dependent | Use condition-specific materials data for engineering calculations. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Common oxidation states | +1 | Source-reviewed; see Sources below | Evaluated |
| Ion / common ion context | K⁺ | Source-reviewed; see Sources below | Evaluated |
| Periodic chemistry context | Potassium begins Period 4 in Group 1, directly below sodium. Its [Ar] 4s¹ configuration continues the alkali-metal pattern: one outer s electron, low first ionization energy and strong +1 chemistry. | Element-specific interpretation | Reviewed |
| Chemistry caution | Elemental form, ions and compounds are distinct chemical objects. | Interpretive teaching rule | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| ³⁹K | Stable · ≈93.258% natural abundance | The dominant naturally occurring isotope; 19 protons and 20 neutrons. | Evaluated |
| ⁴⁰K | Radioactive · ≈0.0117% natural abundance | A long-lived natural radionuclide important in geochronology and natural background radioactivity. | Evaluated |
| ⁴¹K | Stable · ≈6.730% natural abundance | The second stable naturally occurring isotope. | Evaluated |
| Teaching nucleus | ³⁹K · 19 protons + 20 neutrons | Reference isotope used in the nucleus model | Reviewed |
Is Potassium a solid, liquid or gas? State at temperature
On this approximately standard-pressure teaching path, potassium is solid below 336.7 K, liquid between 336.7 K and 1032 K, and gaseous above 1032 K.
Where on Earth is Potassium found or produced?
Who discovered Potassium, and when?
Humphry Davy isolated potassium by electrolysis of caustic potash, making it one of the first metals isolated using the new electrochemical approach.
The name potassium came from “potash,” while the symbol K comes from the Neo-Latin kalium.
Potassium salts became central to modern fertilizer systems as crop nutrient management expanded.
Potassium chemistry spans agriculture, physiology, industrial salts and isotope science.
From potash minerals to potassium compounds: an industrial overview
Potassium occurs naturally in minerals and dissolved salts rather than as free metal because elemental potassium is highly reactive.
Mining and solution-recovery operations obtain potassium-bearing raw materials for potash products.
Processing separates and upgrades potassium salts for fertilizer and industrial specifications.
Agricultural use returns potassium to soils; recovery and recycling are material-flow questions distinct from elemental-metal chemistry.
What is potassium used for?
Fertilizers
Potassium is a primary plant nutrient; potash fertilizers are the largest use of potassium compounds.
Biology & medicine
K⁺ is physiologically essential. Medical potassium products are used under appropriate clinical guidance; this page does not provide dosing advice.
Glass & chemicals
Potassium carbonate, hydroxide and other salts support glassmaking, soaps and chemical synthesis.
Scientific dating
The radioactive isotope ⁴⁰K underpins potassium-argon and related geochronology methods.
Potassium isotopes and natural abundance
³⁹K
Stable · ≈93.258% natural abundanceThe dominant naturally occurring isotope; 19 protons and 20 neutrons.
⁴⁰K
Radioactive · ≈0.0117% natural abundanceA long-lived natural radionuclide important in geochronology and natural background radioactivity.
⁴¹K
Stable · ≈6.730% natural abundanceThe second stable naturally occurring isotope.
Five-question Potassium check
How many valence electrons does neutral potassium have?
Which ion does potassium most commonly form?
What crystal structure does potassium metal have near room temperature?
Which isotope is naturally radioactive?
What does “potash production” usually describe?
Potassium questions students commonly ask
Each answer starts with the direct fact, then explains the chemistry, evidence or material context so the result is understandable rather than merely memorized.
Is potassium a metal?
Short answer: Yes. Potassium is a Group 1 alkali metal. The familiar K⁺ ions in foods, cells and salts are potassium in ionic form, not pieces of potassium metal.
This guide classifies Potassium as an alkali metal. Its periodic position is Period 4, s-block, Group 1. Potassium begins Period 4 in Group 1, directly below sodium. Its [Ar] 4s¹ configuration continues the alkali-metal pattern: one outer s electron, low first ionization energy and strong +1 chemistry.
Key point: Periodic-table classification describes recurring atomic/chemical behavior; it does not make every element in a column physically identical.
How many valence electrons does potassium have?
Short answer: One. Its neutral ground-state configuration ends [Ar] 4s¹.
The neutral-atom ground-state reference used on this page is [Ar] 4s¹. This is an isolated-atom reference: bonding and ion formation can change which outer electrons are present or chemically active. The listed common oxidation-state context is +1, which helps connect the atomic configuration to ordinary chemistry without treating electron counting as a single universal rule.
Key point: Electron configuration is a ground-state atomic reference, not a literal picture of every compound.
How many protons, neutrons and electrons are in potassium?
Short answer: Every potassium atom has 19 protons. A neutral atom has 19 electrons. The common isotope ³⁹K has 20 neutrons; other isotopes have different neutron counts.
Atomic number is defined by proton count, so 19 protons are what make an atom potassium. A neutral potassium atom also has 19 electrons, while isotopes can have different neutron counts without changing the element.
Key point: Atomic number = proton count.
What is potassium’s atomic number and symbol?
Short answer: Atomic number 19 and symbol K. The K comes from kalium.
The symbol K is the standardized chemical abbreviation for element 19. In a chemical formula, K identifies potassium atoms; a compound containing K is not automatically the same material as elemental potassium.
Key point: K always identifies element 19.
Where is potassium found?
Short answer: Potassium is widespread in minerals, soils, seawater and living organisms, but its reactivity means it is normally found in compounds rather than as native metal.
Potassium occurs naturally in minerals and dissolved salts rather than as free metal because elemental potassium is highly reactive. The Geography Explorer keeps natural occurrence separate from resources, industrial production and recycling, because those datasets answer different questions about potassium.
Key point: Natural occurrence, resources, production and recycling are different geography questions.
Why is potassium important to plants and people?
Short answer: K⁺ is an essential ion in cells. Plants require potassium as a major nutrient, and human physiology uses potassium gradients in processes such as nerve and muscle function.
Potassium is a soft Group 1 alkali metal whose single 4s valence electron explains the strong tendency to form K⁺. In nature it occurs in compounds, while potassium ions are essential in cells and potassium salts are central to fertilizers. Fertilizers Potassium compounds are one of the three major fertilizer nutrient families; potash commodities replenish potassium removed from agricultural soils.
Key point: The mechanism matters: connect the observed behavior to electron structure, bonding, phase or the specific material form rather than memorizing the result alone.
Scientific sources for Potassium
- Royal Society of Chemistry - Potassium
- NIST - Atomic Data for Potassium
- USGS - Mineral Commodity Summaries 2026
- WebElements - Potassium crystal structure
Questions to ask next about Potassium
A good element lesson should lead to the next useful question, not end after a list of facts.
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