Strontium

Strontium (Sr)

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.
Atomic Number38
Atomic Weight87.62
Mass Number88
Group2
Period5
Blocks
Protons38 p+
Neutrons50 n0
Electrons38 e-
Strontium destilled crystals.jpg Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
200 pm
Atomic Volume
Covalent Radius
185 pm
Metallic Radius
191 pm
Ionic Radius
118 pm
Crystal Radius
132 pm
Van der Waals radius
249.00000000000003 pm
Density
2.64 g/cm³
Boiling Point
1,657 K
Melting Point
1,042 K
Electrons per shell2, 8, 18, 8, 2
Electronegativity
0.95
Electrophilicity
0.7300624069226 eV/particle
Proton Affinity
Electron Affinity
Ionization Potential
5.6948672 eV/particle
Heat of Vaporization
144 kJ/mol
Heat of Fusion
9.2 kJ/mol
Heat of Formation
164 kJ/mol
Molar Heat Capacity
26.79 J/(mol K)
Specific Heat Capacity
0.306 J/(g⋅K)
Thermal Conductivity
Gas Basicity
Dipole Polarizability
197.2 a₀
C6 Dispersion Coefficient
3,175 a₀
Oxidation States1, 2
Color
Silver
Crystal StructureFace Centered Cubic (FCC)
Lattice Constant
6.08 Å
Bulk Modulus
Electrical Resistivity
Electron Configuration[Kr] 5s2
Magnetic Ordering
Magnetic Susceptibility
PhaseSolid
Poisson Ratio
Shear Modulus
Young's Modulus
Allotropes
Alternate Names
Adiabatic Index
Appearance
Electric Conductivity
Critical Pressure
Critical Temperature
Curie Point
Electrical
Hardness
Magnetic Susceptibility
Magnetic
Neel Point
Neutron Cross Section
Neutron Mass Absorption
Gas Phase
Quantum Numbers
Refractive Index
Space Group
Speed of Sound
Superconducting Point
Thermal Expansion
Valence Electrons
Classification
CategoryAlkaline earth metals, Alkaline earth metals
CAS GroupIIA
IUPAC GroupIIA
Glawe Number15
Mendeleev Number8
Pettifor Number15
Geochemical Classalkaline earth metal
Goldschmidt Classlitophile
Radioactivity
RadioactiveNo
Decay Mode
Half-Life
Lifetime
Abundance
Abundance in Earth's crust
370 mg/kg
Abundance in Oceans
7.9 mg/L
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universe4×10-6%

Isotopes of Strontium

Stable Isotopes
84Sr 86Sr 87Sr 88Sr
Unstable Isotopes
73Sr 74Sr 75Sr 76Sr 77Sr 78Sr 79Sr 80Sr 81Sr 82Sr 83Sr 85Sr 89Sr 90Sr 91Sr 92Sr 93Sr 94Sr 95Sr 96Sr 97Sr 98Sr 99Sr 100Sr 101Sr 102Sr 103Sr 104Sr 105Sr

History

Strontium was recognized as a new element in 1790 when Adair Crawford and his colleague William Cruickshank analyzed a mineral sample from a lead mine near Strontian, Scotland. The element was eventually isolated by Sir Humphry Davy in 1808. The isolation was done by the electrolysis of a mixture containing strontium chloride and mercuric oxide. Named after Strontian, a town in Scotland

DiscoverersA. Crawford
Discovery LocationScotland
Discovery Year1790
Name OriginFrom the Scottish town, Strontian.
Strontium's non-radioactive isotopes are considered non-toxic
Strontium metal turns yellow when exposed to air

Uses

The primary use for strontium is in glass for color television cathode ray tubes. Strontium salts are used in flares and fireworks for a crimson color. Strontium chloride is used in toothpaste for sensitive teeth. Strontium oxide is used to improve the quality of pottery glazes. Used in flares and fireworks for crimson color. Strontium-90 is a long lived highly radioactive fallout product of atomic-bomb explosions.

Sources

Found in minerals celestite and strontianite.