Potassium

Overview

English Name:

Potassium

Latin Name:

Kalium

Year Discovered:

1807

Discovered By:

Sir Humphry Davy

Group:

1

Period:

4

Electrons:

19

CAS Number:

7440-09-7

Cost Per 100 Grams:

$1.00

Atomic Properties

Electronic Configuration:

[Ar] 4s¹

Ion Charge:

+1

Ionisation Energies:

418.8 kJ/mol

Atomic Radius (Empirical):

227 pm

Atomic Radius (Calculated):

227 pm

Covalent Radius:

N/A

Van Der Waals Radius:

275 pm

Ionisation Potential of An Atom:

4.34 eV

Electrons Per Layer:

2, 8, 8, 1

Atomic Multiplicities Of The Gas:

1

Atomic Weight:

39.098

Reactivity

Electron Affinity:

48 kJ/mol

Valence:

1

Electronegativity:

0.82

Thermal Properties

Melting Point:

63.5°C

Boiling Point:

759°C

Critical Point:

Pressure: 2.2 MPa

Temperature: 1032°C

Thermal Conductivity:

0.102 W/(m·K)

Heat Capacity:

Specific: 0.75 J/(g·K)

Molar: 29.93 J/(mol·K)

Thermal Coefficient:

0.00054

Enthalpy:

Fusion: 2.77 kJ/mol

Vaporisation: 77.0 kJ/mol

Atomization: 0.0 kJ/mol

Curie Temperature:

N/A

Neel Temperature:

N/A

Superconductivity Point:

N/A

Physical and Chemical Properties

State of matter (25° C/ 77°F):

Solid

Density:

Solid: 0.89 g/cm³

Molar Volume (Vmol):

27.2 L/mol

Speed of Sound (Vs):

2200 m/s

Hardness:

N/A

Bulk Modulus (K):

N/A

Shear Modulus (G):

N/A

Young's Modulus (E):

N/A

Color:

Silvery-white

Brinell Hardness (MPa):

N/A

Liquid Density (Kg/m^3):

N/A

Hardness of Mohs:

N/A

Refractive Index:

N/A

Vickers Hardness (MPa):

N/A

Crystal Structure:

N/A

Electromagnetic Properties

Electrical Type:

Conductor

Resistivity:

20 × 10^-8 Ω·m

Magnetic Type:

Diamagnetic

Superconductivity:

Not applicable

Volume Magnetic Susceptibility:

-1.0 × 10^-9

Mass Magnetic Susceptibility:

-1.2 × 10^-9 m³/kg

Molar Mass Susceptibility:

-2.0 × 10^-8 m³/mol

Electrical Conductivity:

10^6 S/m

Mass (γ_mass):

3.856 × 10^-26 kg

Mass (γ_mol):

3.856 × 10^-23 mol

Volume (γ_vol):

27.2 L

Grid Parameters

Crystal Structure:

N/A

Grid Parameters:

N/A

Attitude:

N/A

Debye Temperature:

N/A

Safety and Precautions

Signal Word:

Warning

Hazard Statements:

H260

Precautionary Statements:

P210, P223

RTECS Number:

Not available

Risk:

Flammability: Flammable
Health Risk: Harmful if inhaled
Reactivity: Stable
Specific Risk: None

Importance

Main sources:

Minerals, fertilizers

Main Usage:

Fertilizers, food preservation, and as a salt substitute

Nuclear Properties

Radioactive:

No

Isotopes:

K-39, K-40, K-41

Neutron Cross Sectional:

0.025 barns

Half Life (s):

None

Lifetime:

Stable

Prevalence

Universe:

0.012%

Sun:

0.012%

Oceans:

0.0004%

Humans:

0.0002%

Earth's Crust:

2.4%

Meteorites:

0.0004%