Potassium (K) – Periodic Table [Element Information & More]

Potassium element (K) is in group 1 and period 4 of a periodic table. Potassium is in the s-block and it is classified as an alkali metal on the periodic table.

There is a lot more information related to potassium which is mentioned in the Information Table given below.

So let’s dive right into it!

Table of contents

• Potassium element (Information Table)
• Potassium element in Periodic table
• Facts about Potassium
• Properties of Potassium
• Uses of Potassium

Potassium Element (Information Table)

The important data related to potassium element is given in the table below.

Appearance of potassium	Silvery gray
Atomic number of potassium	19
Symbol of potassium	K
Atomic mass of potassium	39.098 u
Protons, Neutrons & Electrons in potassium	Protons: 19, Neutrons: 20, Electrons: 19
State of potassium (at STP)	Solid
Group number of potassium in periodic table	1
Period number of potassium in periodic table	4
Block of potassium in periodic table	s-block
Category of potassium	Alkali metal
Bohr model or Electrons per shell or Electrons arrangement in potassium	2, 8, 8, 1
Electron configuration of potassium	[Ar] 4s1
Orbital diagram of potassium
Valence electrons in potassium	1
Electronegativity of potassium (on pauling scale)	0.82
Atomic radius of potassium (van der Waals radius)	275 picometers
Density of potassium	0.856 g/cm3
1st ionization energy of potassium	4.341 eV
Main isotope of potassium	39K
Melting point of potassium	336.7 K or 63.5 °C or 146.3 °F
Boiling point of potassium	1032 K or 759 °C or 1398 °F
Crystal structure of potassium	Body Centered Cubic (BCC)
Discovery of potassium	By Humphry Davy in 1807

Also see: Interactive Periodic Table (It has rotating bohr models as well as many other details of all the 118 elements in a single periodic table).

Potassium element in Periodic table

The Potassium element (K) has the atomic number 19 and is located in group 1 and period 4. Potassium is in solid state at STP and it is classified as an alkali metal on the periodic table.

Click on above elements in the periodic table to see their information.

Facts about potassium

Here are a few interesting facts about potassium element.

1. 2.4% of the earth’s crust consists of potassium element.
2. Potassium is the 7th most abundant element present in the earth’s crust.
3. Human body also contains potassium in trace amounts.
4. If potassium is deficient in the human body, then it can cause hypokalemia.
5. The dead sea has a lot of potassium in it.
6. Potassium floats on water as it is lighter than water.
7. Potassium is a soft metal and you can even cut it with a knife.

Properties of potassium

Here is a list of some physical properties and chemical properties of potassium.

Physical properties of potassium

• Potassium is a solid metal having a shiny-gray appearance.
• Potassium gets a dull gray color if it is kept open in the air. This is because of oxide layer formation on the surface of potassium metal.
• After lithium, potassium is the 2^nd lightest metal.
• The potassium element has a density less than that of water, hence it floats on water.
• There are many isotopes of potassium, and out of these isotopes, the most abundant isotope is ³⁹K, which has an abundance of around 93%.
• The melting point and boiling point of potassium is 336.7 K and 1032 K respectively.

Chemical properties of potassium

• Potassium is not found in its free state because of its high reactivity. It is always found as a compound with other elements on the earth’s crust.
• Potassium reacts violently with water.
• Potassium releases hydrogen gas when it reacts with water and this reaction makes the solution alkaline.
• Potassium is always stored in a mineral oil because of its reactivity.

Uses of potassium

Here are some uses of the potassium element.

• Potassium is used in the manufacturing of fertilizers, oxidizers, etc.
• Potassium bisulfate is used to preserve wines and beer.
• Nuts, potatoes, tomatoes, etc have potassium in it. Human body also requires potassium for maintaining proper health.
• Potassium bromide, which is a compound of potassium, is used in medicinal applications as well as in photography.
• Potassium is used in manufacturing of glass, soap, bleaching agents as well as gunpowder.

External resources:

1. Potassium – Wikipedia. (2019, April 17). Potassium – Wikipedia. https://en.wikipedia.org/wiki/Potassium
2. It’s Elemental – The Element Potassium. (n.d.). It’s Elemental – the Element Potassium. https://education.jlab.org/itselemental/ele019.html
3. Periodic Table of Elements: Los Alamos National Laboratory. (n.d.). Periodic Table of Elements: Los Alamos National Laboratory. https://periodic.lanl.gov/19.shtml
4. Potassium | K | ChemSpider. (n.d.). Potassium | K | ChemSpider. http://www.chemspider.com/Chemical-Structure.4575326.html?rid=1a1ec1c6-d152-4a4c-9859-a8500d526eeb&page_num=0
5. C&EN: IT’S ELEMENTAL: THE PERIODIC TABLE – POTASSIUM. (n.d.). C&EN: IT’S ELEMENTAL: THE PERIODIC TABLE – POTASSIUM. https://pubsapp.acs.org/cen/80th/potassium.html?
6. Haynes, W. M. (Ed.). (2014, June 4). CRC Handbook of Chemistry and Physics. https://doi.org/10.1201/b17118
7. Emsley, J. (2011). Nature’s Building Blocks: An A-Z Guide to the Elements. United Kingdom: OUP Oxford.
8. Sansonetti, J. E., & Martin, W. C. (2005, December). Handbook of Basic Atomic Spectroscopic Data. Journal of Physical and Chemical Reference Data, 34(4), 1559–2259. https://doi.org/10.1063/1.1800011
9. Bondi, A. (1964, March). van der Waals Volumes and Radii. The Journal of Physical Chemistry, 68(3), 441–451. https://doi.org/10.1021/j100785a001
10. James A. M. & Lord M. P. (1992). Macmillan’s chemical and physical data. Macmillan.
11. Holden, et al. (2018, December 1). IUPAC Periodic Table of the Elements and Isotopes (IPTEI) for the Education Community (IUPAC Technical Report). Pure and Applied Chemistry, 90(12), 1833–2092. https://doi.org/10.1515/pac-2015-0703
12. Allred, A. (1961, June). Electronegativity values from thermochemical data. Journal of Inorganic and Nuclear Chemistry, 17(3–4), 215–221. https://doi.org/10.1016/0022-1902(61)80142-5
13. Kaye, G W.C., & Laby, T H. Tables of physical and chemical constants. 15th Edition. United States.
14. Zhang, Y., Evans, J. R. G., & Yang, S. (2011, January 11). Corrected Values for Boiling Points and Enthalpies of Vaporization of Elements in Handbooks. Journal of Chemical & Engineering Data, 56(2), 328–337. https://doi.org/10.1021/je1011086
15. Possolo, A., van der Veen, A. M. H., Meija, J., & Hibbert, D. B. (2018, January 4). Interpreting and propagating the uncertainty of the standard atomic weights (IUPAC Technical Report). Pure and Applied Chemistry, 90(2), 395–424. https://doi.org/10.1515/pac-2016-0402