Elements
19

K

Potassium

Potassium (K) is a silver-white coloured metal that has the atomic number 19 in the periodic table. It is an Alkali Metal and is located in Group 1 of the periodic table. it has the symbol K.

Potassium is a highly reactive metal in Group 1 of the periodic table. Potassium like the other alkali metals needs to be stored in oil to prevent reactions with the moisture and oxygen in the air, it can also be cut with a knife and reacts violently with water to produce a lilac flame. Potassium was first isolated from Potash (the ash of plants) from which its name is given. Georg Ernst Stahl conducted the first experiments on Potash in 1702 but it was not until 1807 that Sir Humphry Davy isolated potassium from Potassium Hydroxide, a common solution containing Potassium, using a voltaic pile. Being in Group 1 and having one valence electron, Potassium likes to exist in compounds and is not found naturally in the earths crust. It is commonly found in sea water and in minerals in the earth’s crust. Potassium’s main use is in fertiliser as a source of potassium for plants, it also has uses in solutions such as Potassium Hydroxide as a strong base for neutralising acids. It is also the ninth most abundant element in the human body where it is used in membranes and hormone secretion. In the human diet it is commonly found in fruits such as Apricots and Bananas as well as milk and soya. It is located in Group 1 as an Alkali metal which is very reactive with water . It has a melting point of 63.5°c and a boiling point of 759°c.

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FAQ's

What is the Melting Point for Potassium?

Potassium has a Melting Point of 63.26°F, meaning at 63.26°F it will turn to a liquid.

What is the Boiling Point for Potassium?

Potassium has a Boiling Point of 760°F, meaning at 760°F it will turn to a Gas.

What is the Electronegativity of Potassium?

Potassium's Electronegativty is 0.82. Electronegativity is a measure of how strongly atoms attract bonding electrons to themselves.

What is the Heat of Vaporization of Potassium?

Potassium has a Heat of Vaporization of 79.87 kJ/mol.

Uses

Used as potash in making glass & soap. Also as saltpeter, potassium nitrate (KNO3) to make explosives and to color fireworks in mauve. Formerly called kalium (K). Vital to function of nerve and muscle tissures.

Sources

Found in minerals like carnallite [(KMgCl3).6H2O] & sylvite (potassium chloride, KCL). Pure metal is produced by the reaction of hot potassium chloride and sodium vapors in a special retort.

19
Protons
19
Electrons
20
Neutrons

K

Element Symbol
K
Atomic Weight
39.098
Atomic Number
19
State
Solid
Melting Point
Unknown
63.26
°C
Boiling Point
760
Unknown
°C
Heat of Vaporization
79.87
Unknown
kJ/mol
Crystal Structure
Cubic: Body centered
Thermoconductivity
1.024
Unknown
W/cmK
Shells
2,8,8,1
Group
Alkali Metal
Period
4
Block
S Block
Orbitals
[Ar] 4s1
Coefficient of Thermal Expansion
82 10^-6 K^-1
Covalent Radius
2.03 Å
Density at 293K
0.862 g/cm³
Electrical Conductivity
0.139 10^6/cm ohm
First Ionization Potential
4.3407 V
Second Ionization Potential
31.625 V
Third Ionization Potential
45.72 V
Ionic Radius
1.51 (+1) Å
Oxydation States
1
Lattice Parameter
5.247 Å
Lattice Parameter 2
--
Lattice Parameter 3
4.6845 Å
Pronounced

pe-TASS-i-em

Discovered by

Sir Humphrey Davy

Discovery date

1807

Orbital configuration
2,8,8,1

Download the Periodic Table

Explore Other Alkali Metals

223
87

Fr

Francium
85.468
37

Rb

Rubidium
6.941
3

Li

Lithium
132.905
55

Cs

Caesium
22.99
11

Na

Sodium
The alkali metals, found in group 1 of the periodic table (formally known as group IA), are so reactive that they are generally found in nature combined with other elements. The alkali metals are shiny, soft, highly reactive metals at standard temperature and pressure.
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