Sr

Strontium

Identification

CAS Number: 7440-24-6

Discovery Year: 1790

Discoverer: A. Crawford

Discovery Location: Scotland

Properties

Atomic Mass: 87.62 →Density: 2.64 g/cm³ →

Crust Abundance: 370 mg/kg

Crystal Structure: FCC

Atomic Dimensions

Atomic Radius: 200 pm →

Atomic Radius (Rahm): 279 pm

Covalent Radius: 195 pm →

Van der Waals Radius: 249.00000000000003 pm

Metallic Radius: 191 pm

Atomic Volume: 33.7 cm³/mol

Lattice Constant: 6.08 Å

Thermodynamics

Melting Point: 1042 K →Boiling Point: 1657 K →Specific Heat: 0.301 J/(g·K) →Heat of Fusion: 9.2 kJ/mol →Heat of Vaporization: 144 kJ/mol →

Heat of Formation: 164 kJ/mol

Electronic Structure

Electron Config: [Kr] 5s2

Block: s

Period: 5 →Group: 2 →Electronegativity: 0.95 →Electron Affinity: 0.048 eV →

Oxidation States: +2

Abundance & Geochemistry

Crust Abundance: 370 mg/kg

Sea Abundance: 7.9 mg/L

Geochemical Class: alkaline earth metal

Goldschmidt Class: litophile

About

Soft yellowish metallic element, belongs to group 2 of the periodic table. Highly reactive chemically. Sr-90 is present in radioactive fallout and has a half-life of 28 years. Discovered in 1798 by Klaproth and Hope, isolated in 1808 by Humphry Davy.

Isotopes

Sr-88 88 82.58%

Sr-86 86 9.86%

Sr-87 87 7.00%

Sr-84 84 0.5600%