Potassium is a chemical element with symbol K (derived from Neo-Latin, kalium) and atomic number 19. It was first isolated from potash, the ashes of plants, from which its name is derived. In the Periodic table, potassium is one of seven elements in column (group) 1 (alkali metals):they all have a single valence electron in their outer electron shell, which they readily give up to create an atom with a positive charge - a cation, and combine with anions to form salts.
It belongs to group 1 of the periodic table having trivial name alkali metals*.
Read key information and facts about element Potassium
|Group in Periodic Table||1|
|Group Name||lithium family|
|Period in Periodic Table||period 4|
|Block in Periodic Table||s -block|
|Electronic Configuration||[Ar] 4s1|
|Electronic Shell Structure (Electrons per shell)||2, 8, 8, 1|
|Melting Point||336.53 K|
|Boiling Point||1032 K|
How to Locate Potassium on Periodic Table
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 19 to find Potassium on periodic table.
Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Potassium on periodic table look for cross section of group 1 and period 4 in the modern periodic table.
The element Potassium was discovered by H. Davy in year 1807 in United Kingdom. Potassium was first isolated by H. Davy in 1807. Potassium derived its name from New Latin potassa, 'potash' (kalium in Latin).
Davy discovered it by using electrolysis on potash.
Potassium Presence: Abundance in Nature and Around Us
The table below shows the abundance of Potassium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
|ppb by weight (1ppb =10^-7 %)||ppb by atoms (1ppb =10^-7 %)|
|Abundance in Universe||3000||100|
|Abundance in Sun||4000||100|
|Abundance in Meteorites||710000||370000|
|Abundance in Earth's Crust||15000000||7800000|
|Abundance in Oceans||416000||65800|
|Abundance in Humans||2000000||320000|
Crystal Structure of Potassium
The solid state structure of Potassium is Body Centered Cubic.
The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.
Unit Cell Parameters
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)
|532.8 pm||532.8 pm||532.8 pm|
and the angles between them Lattice Angles (alpha, beta and gamma).
The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.
The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.
|Space Group Name||Im_ 3m|
|Space Group Number||229|
|Crystal Structure||Body Centered Cubic|
|Number of atoms per unit cell||2|
The number of atoms per unit cell in a simple cubic, face-centered cubic and body-centred cubic are 1,4,2 respectively.
Potassium Atomic and Orbital Properties
Potassium atoms have 19 electrons and the electronic shell structure is [2, 8, 8, 1] with Atomic Term Symbol (Quantum Numbers) 2S1/2.
|Number of Electrons (with no charge)||19|
|Number of Protons||19|
|Number of Neutrons||20|
|Shell structure (Electrons per energy level)||2, 8, 8, 1|
|Electron Configuration||[Ar] 4s1|
|Main Oxidation States||1|
|Oxidation States||-1, 1|
|Atomic Term Symbol (Quantum Numbers)||2S1/2|
Bohr Atomic Model of Potassium - Electrons per energy level
Ground State Electronic Configuration of Potassium - neutral Potassium atom
Abbreviated electronic configuration of Potassium
The ground state abbreviated electronic configuration of Neutral Potassium atom is [Ar] 4s1. The portion of Potassium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Ar]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 4s1, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Potassium
Complete ground state electronic configuration for the Potassium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 4s1
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.
Atomic Structure of Potassium
Potassium atomic radius is 243 pm, while it's covalent radius is 196 pm.
|Atomic Radius Calculated|
243 pm (2.43 Å)
|Atomic Radius Empirical|
220 pm (2.2 Å)
|Atomic Volume||45.68 cm3/mol|
|Covalent Radius||196 pm (1.96 Å)|
|Van der Waals Radius||275 pm|
|Neutron Cross Section||2.1|
|Neutron Mass Absorption||0.0018|
Atomic Spectrum of Potassium
Potassium Chemical Properties: Potassium Ionization Energies and electron affinity
The electron affinity of Potassium is 48.4 kJ/mol.
Ionization Energy of Potassium
Refer to table below for Ionization energies of Potassium
|Ionization energy number||Enthalpy - kJ/mol|
Potassium Physical Properties
Refer to below table for Potassium Physical Properties
|Density||0.856 g/cm3(when liquid at m.p density is $0.828 g/cm3)|
|Molar Volume||45.68 cm3/mol|
|Shear Modulus||1.3 GPa|
|Bulk Modulus||3.1 GPa|
Hardness of Potassium - Tests to Measure of Hardness of Element
|Mohs Hardness||0.4 MPa|
|Brinell Hardness||0.363 MPa|
Potassium Electrical Properties
Potassium is Conductor of electricity. Refer to table below for the Electrical properties ofPotassium
|Electrical Conductivity||14000000 S/m|
|Resistivity||7e-8 m Ω|
Potassium Heat and Conduction Properties
|Thermal Conductivity||100 W/(m K)|
Potassium Magnetic Properties
|Mass Magnetic Susceptibility||6.7e-9 m3/kg|
|Molar Magnetic Susceptibility||2.62e-10 m3/mol|
|Volume Magnetic Susceptibility||0.00000574|
Optical Properties of Potassium
Acoustic Properties of Potassium
|Speed of Sound||2000 m/s|
Potassium Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Potassium
|Melting Point||336.53 K (63.38°C, 146.084 °F)|
|Boiling Point||1032 K (758.85°C, 1397.93 °F)|
|Critical Temperature||2223 K|
Enthalpies of Potassium
|Heat of Fusion||2.33 kJ/mol|
|Heat of Vaporization||76.9 kJ/mol|
|Heat of Combustion||-182 J/(kg K)|
Potassium Isotopes - Nuclear Properties of Potassium
Potassium has 24 isotopes, with between 32 and 55 nucleons. Potassium has 2 stable naturally occuring isotopes.
Isotopes of Potassium - Naturally occurring stable Isotopes: 39K, 41K.
|Isotope||Z||N||Isotope Mass||% Abundance||T half||Decay Mode|
Regulatory and Health - Health and Safety Parameters and Guidelines
|DOT Hazard Class||4.3|
|NFPA Fire Rating||3|
|NFPA Hazards||Water Reactive|
|NFPA Health Rating||3|
|NFPA Reactivity Rating||2|
|Autoignition Point||440 °C|
List of unique identifiers to search the element in various chemical registry databases
|CAS Number - Chemical Abstracts Service (CAS)||CAS7440-09-7|
Compare Potassium with other elements
Compare Potassium with all Group 1 elements
Compare Potassium with all Period 4 elements
Compare Potassium with all Alkali Metal elements
What is the electronic configuration of Potassium?
The electronic configuration of Potassium is 1s2 2s2 2p6 3s2 3p6 4s1.
What is the abbreviated electronic configuration of Potassium?
The abbreviated electronic configuration of Potassium is [Ar] 4s1. To form abbreviated notation of electronic configuration, the completely filled subshells are replaced by the noble gas of the preceding period in square brackets.
What is the symbol of Potassium?
Symbol of Potassium is K. Potassium is a chemical element with symbol K and atomic number 19.
What is the position of Potassium in the Periodic Table?
Potassium is a chemical element with the symbol K and atomic number 19. Potassium is the 19 element on the periodic table. It is located in group 1 and period 4 in the modern periodic table.
What is the atomic number of Potassium?
The atomic number of Potassium is 19.
What is the color of Potassium?
Potassium is of Silver color.
Who discovered Potassium?
The element Potassium was discovered by H. Davy in year 1807 in United Kingdom. Potassium was first isolated by H. Davy in 1807.
How many valence electrons does a Potassium atom have?
Potassium has 1 valence electrons. Potassium has 19 electrons out of which 1 valence electrons are present in the 4s1 outer orbitals of atom.
What is the melting Point of Potassium?
Melting Point of Potassium is 336.53 K.
What is the boiling Point of Potassium?
Boiling Point of Potassium is 1032 K.
What is the melting Point of Potassium in Kelvin?
Melting Point of Potassium in Kelvin is 336.53 K.
What is the boiling Point of Potassium in Kelvin?
Boiling Point of Potassium in Kelvin is 1032 K.
What is the electronic configuration of Potassium 19?
The electronic configuration of Potassium will be 1s2 2s2 2p6 3s2 3p6 4s1.
How do you write the electron configuration for Potassium?
The electronic configuration of Potassium will be 1s2 2s2 2p6 3s2 3p6 4s1.