The 19th element of the Period Table, Potassium is one of the most important elements necessary for life. Did you know that absence of Potassium in the human body will make our body dysfunctional? We will go there later. Anyway, in this article on Potassium facts, we will walk you through a lot of things like the discovery of the element, characteristics, uses and more. So, without further ado, let us begin.
Facts about Potassium – Some Basic Information at a Glance
|Element Family||Alkali metal|
|Melting Point||63.4˚C or 336.5 K|
|Boiling Point||765.6˚C or 1038.7 K|
|Density at 20˚C||0.862 g/cm3|
|Number of Electrons||19|
|Number of Protons||19|
|Number of Neutrons (as found in the most abundant isotope)||20|
|Electronic Configuration||1s2 2s2 2p6 3s2 3p6 4s1|
|Known Isotopes||24 know isotopes so far|
|Element Structure||Body-centered cubic|
|Atomic Radius||220 pm|
Okay, now that we have some basic information in hand, it is time for us to take a quick look at the various isotopes of the element.
Facts about Potassium – Potassium Isotopes
|Isotope Name||Type and Abundance||Half-Life (HL)|
|35K||Radioactive||178 (8) ms|
|36K||Radioactive||342 (2) ms|
|37K||Radioactive||1.226 (7) s|
|38K||Radioactive||7.636 (18) min|
|39K||Stable and 93.258 natural abundance||Stable and hence, no HL|
|40K||Radioactive and 0.012% natural abundance||~ 1.25 billion years|
|41K||Stable and 6.730% natural abundance||Stable and hence, no HL|
|42K||Radioactive||12.360 (12) h|
|43K||Radioactive||22.3 (1) h|
|44K||Radioactive||22.13 (19) min|
|45K||Radioactive||17.3 (6) min|
|46K||Radioactive||105 (10) s|
|47K||Radioactive||17.50 (24) s|
|48K||Radioactive||6.8 (2) s|
|49K||Radioactive||1.26 (5) s|
|50K||Radioactive||472 (4) ms|
|51K||Radioactive||365 (5) ms|
|52K||Radioactive||105 (5) ms|
|53K||Radioactive||30 (5) ms|
|54K||Radioactive||10 (5) ms|
#: Data not derived from pure experimental data but partly derived from systematic trends.
(*): Value in parentheses [such as (1)] after the last digit represents uncertainties in a concise form. These uncertainty values represent one standard deviation.
Now that we have all the basic information in hand, we can proceed with the Potassium facts. Let us begin.
Potassium Facts: 1-10 | History and Discovery
1. The element Potassium was first discovered by Sir Humphry Davy in the year 1807.
2. In 1806, Davy found out something truly fascinating. He saw that he can easily break any substance into their individual elements or building blocks using electricity. He understood that the nature of chemical bonding was electrical.
3. So, in 1807, while he was in Royal Institution, London, he took Potash or Potassium Hydroxide and moistened it slightly by keeping it in moist air.
4. He then electrolyzed the substance by using three large batteries that he himself had built.
5. The result of this experiment was that Potassium was isolated for the very first time.
6. During the process, when he passed the electricity through his batteries to Potash, tiny globules accumulated on the anode – the negatively charged electrode.
7. Those tiny globules displayed a very distinctive metallic luster.
8. Humphry Davy was not the only person conducting the experiment. Another person called Edmund Davy was helping him.
9. According to Edmund, the moment in which Humphry Davy succeeded in isolating Potassium was his ‘Eureka’ moment!
10. Humphry Davy was ecstatic and according to Edmund, when Humphry Davy saw the Potassium globules bursting out through the crust of the Potash, he started dancing.
Potassium Facts: 11-15 | Humphry Davy’s Observations
11. Humphry Davy observed quite a few things about Potassium. The first thing he noted was that the density of the element was extremely low. He dropped some Potassium into oil only to see that it started floating!
12. Sir Humphry Davy then decided to drop a piece of Potassium into the water. To his astonishment, Davy found that it reacted violently.
13. When Potassium came in contact with water, there was an instantaneous explosion. Along with the explosion, the reaction also yielded a brilliant flame.
14. Following these two observations, Davy dropped a piece of the metal into HCL or Hydrochloric Acid. When the metal came in contact with the acid, it burned, yielding a bright flame that was red in color.
15. A few days after Humphry Davy discovered Potassium, he managed to isolate Sodium as well using the same electrolysis method.
Potassium Facts: 16-27 | Potassium Etymology
16. The name Potassium comes from Potash. Potash actually refers to the extraction methods that were used during the early days for extracting various salts of Potassium.
17. The method involved placing ash created by burning tree leaves or burnt wood in a pot. People would then add water into the pot. They would then heat and evaporate the solution to get various Potassium salts.
18. However, the element has a very weird symbol. The symbol that we use for denoting Potassium is K.
19. The symbol is derived from the term ‘kali.’ Kali is in turn derived from ‘alkali’. Alkali, in turn, is derived from ‘al-qalyah’ – an Arabic term which means ‘plant ashes’.
20. The name ‘kali’ has an interesting story associated with it. Martin Klaproth – a German chemist was working with two minerals named Lepidolite and Leucite in the year 1797.
21. Klaproth discovered Potash in those two minerals. He instantly realized that Potash was not something that came only from plant growth.
22. Klaproth understood that Potash contained a completely new element. He proposed that the new element (yet not discovered) should be named as kali.
23. In 1807, Humphry Davy isolated Potassium using electrolysis. Four years later in 1809, a new name for Potassium was proposed by Ludwig Wilhelm Gilbert. He suggested that Potassium, as named by Davy should be named as Kalium.
24. Berzelius – a chemist from Sweden staunchly advocated the name Kalium in 1814. He suggested that the symbol should be K.
25. Later, the countries speaking French and English went on to adopt the name Potassium that was given by Gay-Lussac/Thénard and Davy.
26. On the other hand, Klaproth/Gilbert name, Kalium, was adopted by the Germanic countries.
27. The International Union of Physical and Applied Chemistry has something called ‘Gold Book’. In that book, the name ‘Potassium’ has been selected while the symbol ‘K’ has been selected. That is what we use today.
Potassium Facts: 28-46 | Properties of Potassium
In this segment, we will learn about the physical and chemical properties of the element. Albeit, we will not go too deep but we will mention all important properties.
Potassium Facts – Properties of Potassium (Physical)
29. If Potassium did not react with water, it would easily float on water. Unfortunately, when Potassium comes in contact with water, it explodes violently. So, you cannot see Potassium floating on water.
30. The metal is very soft. You can literally cut it using a knife.
31. When you cut a piece of Potassium, you will find the color on the cut sides to be silvery. However, the metal will become dull and greyish as soon as it comes in contact with air.
32. Do you know what is a flame test? It is a test in which chemists will burn a substance to detect the presence of elements. They will observe the color of the flame. It turns out that whenever you burn Potassium or any of its compounds, you will see a lilac-colored flame.
Potassium Facts – Properties of Potassium (Chemical)
Now that we have learned about the physical properties of Potassium, let us take a look at the chemical properties of Potassium.
33. Neutral atoms of Potassium (that is, stable isotopes) have a total of 19 electrons each. Argon (the most stable noble gas in the world) has 18 electrons in each atom. So, Potassium has one more electron – known as the valence electron.
34. Since there is only one electron in the outermost shell of the atom, a Potassium atom is more likely to give it up to get a positive charge during a chemical reaction. It will not really try to get a negative charge by accepting an electron from another compound.
35. The question is, why will a Potassium atom want to give up the valence electron? Simple! It will want to achieve the stability of a noble gas such as Argon.
36. We said that Potassium reacts violently with water. Why? When you drop a piece of Potassium in water, it will react with the Oxygen present in water.
37. What happens during the reaction between Potassium and water? Potassium reacts with Oxygen in water and releases Hydrogen. The Hydrogen that is released reacts back with Oxygen present in the atmosphere.
38. The water that Hydrogen forms by reacting with Oxygen in the atmosphere react back with the rest of the Potassium.
39. The reaction between Potassium and water is exothermic. What is an exothermic reaction? It is a type of reaction in which heat is released.
40. Leave a piece of pure Potassium in the open air and it will immediately turn dull and acquire a greyish color. It happens because Potassium readily reacts with Oxygen present in the atmosphere.
41. When Potassium and water come together, they form Potassium Hydroxide. When Potassium reacts with Oxygen in air, it forms Potassium Peroxide.
42. Since Potassium is extremely sensitive towards both Oxygen and water, the only way to make Potassium react with some other element is to conduct the reactions in an inert atmosphere (such as inside a chamber filled with Argon and absolutely no Oxygen).
43. Potassium cannot react with various hydrocarbons like kerosene or mineral oils.
44. At a temperature of 0˚C, Potassium can quickly dissolve in liquid ammonia. Nearly 480 grams of Potassium can dissolve in 1000 grams of ammonia.
45. When Potassium is dissolved in ammonia, the color of the resulting solution can be yellow or blue. The color is dependent on the concentration of Potassium in ammonia.
46. Yet another interesting Potassium fact is that the Potassium-ammonia solution has similar electrical conductivity as that of liquid metals.
Potassium Facts: 47-53 | Interesting Facts about Potassium
47. Both Potassium (K) and Sodium (Na) are solid at room temperature. However, when the two are combined to form an alloy, the resulting alloy is liquid at room temperature.
48. In general, the NaK alloy contains anywhere between 40% and 90% Potassium. The commercial-grade NaK alloy that contains 22% Na and 78% K has the ability to remaining liquid at a temperature of -12.6˚C or 9.3˚F.
49. 40K – the radioactive isotope of Potassium gradually decays into 40Ar (the stable isotope of Argon) and 40Ca (the stable isotope of Calcium). Because 40K has a half-life of 1.25 billion years, it is used for dating rocks that are extremely old.
50. The method that scientists use for dating rock is that of measuring the ratio of Potassium-40 to Argon-40 that is trapped inside a rock. This ratio gives a clear idea of how old the rock is.
51. Most of the Potassium atoms that are found in the universe came from Supernova explosions. When the shells of large stars explode in a Supernova explosion, Oxygen burns to make Potassium.
52. The method in which Potassium is produced in stars is not really a normal burning but nonetheless, it is nuclear fusion reaction which leads to explosive burning of Oxygen that churns out Potassium.
53. Potassium is the 7th most abundant element found in the crust of the Earth (according to the Royal Society of Chemistry). The element accounts for roughly 2.4% of the mass of the crust.
Potassium Facts: 54-65 | Potassium in Human Body and Other Life Forms
54. Did you know that Potassium is the 7th most abundant element in the human body? This means that the element is actually essential for life. As a matter of fact, the element is found in all living organisms on this planet.
55. Potassium is responsible for maintaining electrolyte and fluid balance. Potassium ions are found in each and every cell of the human body as well as other organisms. Potassium ions in cells are cations (a positively charged ions).
56. According to the Royal Society of Chemistry, though 40K has very mild radioactivity, it may actually be one of the natural causes that leads to genetic mutations in humans.
57. If the levels of Potassium in human body drop significantly, it leads to a situation or health condition that we know as Hypokalemia.
58. University of Maryland Medical Center says that Hypokalemia is associated with a number of symptoms that include:
- Irregular heartbeat.
- Muscle cramps, etc.
59. There are around 140 grams of Potassium stored in all cells of the human body.
60. On an average, a human being consumes 7 grams of the element each day.
62. According to Chemicool, there are several neurotoxins that actually impact the cells in a way that they fail to use Potassium properly. Such neurotoxins can lead to extreme pains, or in worst case scenarios, lead to death.
63. Some such neurotoxins include:
- Dendrotoxin (bites from Mamba snakes)
- Apamin (bee stings)
- Margatoxin (scorpion stings)
64. The Royal Society of Chemistry says that plants have a higher concentration of Potassium in their cells because they get the element from the soil.
65. It is necessary, according to the RSC, the agricultural lands from which harvests are taken each year, require Potassium replenishment after each harvest. The easiest way of replenishment is that of adding fertilizers that are Potassium-based.
Potassium Facts: 66-71 | Uses of Potassium
66. A compound of Potassium known as the Potassium Nitrate is used for explosives, gunpowder, and fireworks. Potassium Nitrate contains Potassium, Oxygen, and Nitrogen.
67. Potassium Hydroxide – yet another compound of Potassium is used for dish wash soap and detergent making.
68. Perhaps one of the most popular uses of Potassium is in the fertilizer industry. Potassium compounds are used as fertilizers in both agriculture and horticulture.
69. A white crystalline salt of Potassium known as Potassium Bromide is widely used in photography and medicinal products.
70. One of the commonest uses of Potassium as a portable oxygen source. KO2 – Potassium Superoxide – is used for releasing Oxygen by absorbing Carbon Dioxide. KO2 is an orange solid and it is usually used in respiration systems of mines, spacecraft, and submarines.
71. One of the methods of making toughened glass is to insert the glass in molten KNO3 (Potassium Nitrate).