Kalium

19
K
Gruppe
1
Periode
4
Blok
s
Protons
Electrons
Neutrons
19
19
20
General Properties
Atomnummer
19
Atommasse
39,0983
Mass Number
39
Kategori
Alkalimetaller
Farve
Silver
Radioactive
Nej
From the English word, potash - pot ashes; Latin kalium, Arab qali, alkali
Krystalstruktur
Rumcentreret Kubisk
History
Potassium's symbol K comes from 'kalium' the name of the element in Germany and Scandinavia.

Potassium metal was first isolated in 1807 by Sir Humphry Davy, who derived it from caustic potash by the use of electrolysis of the molten salt with the newly discovered voltaic pile.

Potassium was the first metal that was isolated by electrolysis.
Elektroner i hver skal
2, 8, 8, 1
Elektronkonfiguration
[Ar] 4s1
K
People whose diets are low in potassium can suffer from hypokalemia
Physical Properties
Tilstandsform
Fast stof
Massefylde
0,862 g/cm3
Smeltepunkt
336,53 K | 63,38 °C | 146,08 °F
Kogepunkt
1032,15 K | 759 °C | 1398,2 °F
Smeltevarme
2,33 kJ/mol
Fordampningsvarme
76,9 kJ/mol
Varmefylde
0,757 J/g·K
Abundance in Earth's crust
1,5%
Abundance in Universe
0,0003%
Potassium
Billede akkrediteringer: Images-of-elements
Potassium pearls under paraffin oil
CAS Number
7440-09-7
PubChem CID Number
5462222
Atomic Properties
Atomradius
227 pm
Kovalent radius
203 pm
Elektronegativitet
0,82 (Paulings skala)
Ionization Potential
4,3407 eV
Atomic Volume
45,46 cm3/mol
Varmeledningsevne
1,024 W/cm·K
Oxidationstrin
-1, 1
Applications
The greatest demand for potash has been in its use for fertilizers.

Potassium is an essential constituent for plant growth and is found in most soils.

Potassium nitrate is the main explosive ingredient in gunpowder.

Potassium hydroxide is used in the manufacture of soft soaps and as an electrolyte in alkaline batteries.
Potassium must be handled with great care with full skin and eye protection
Isotoper
Stable Isotopes
39K, 41K
Unstable Isotopes
32K, 33K, 34K, 35K, 36K, 37K, 38K, 40K, 42K, 43K, 44K, 45K, 46K, 47K, 48K, 49K, 50K, 51K, 52K, 53K, 54K, 55K