Strontium

Symbol	Sr
Atomic number	38
Group	2 (Alkaline earth metal)
Period	5
Block	s
Classification	Alkaline Earth Metal

Appearance	-
Color	Silver

Number of protons	38 p+
Number of neutrons	50 n0
Number of electrons	38 e-

From Wikipedia, the free encyclopediaStrontium is a chemical element with symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white or yellowish metallic element that is highly reactive chemically. The metal turns yellow when it is exposed to air.

Phase at STP	Solid
Density	2.64 g/cm3
Atomic weight	87.621 u

Melting point	1050 K 776.85 °C 1430.33 °F
Boiling point	1650 K 1376.85 °C 2510.33 °F
Heat of vaporization	136.9 kJ/mol

Electronegativity (Pauling Scale)	0.95
Electron affinity	5.023 kJ/mol
Oxidation states	+1, +2 (a strongly basic oxide)
Ionization energies	549.5 kJ/mol 1064.2 kJ/mol 4138 kJ/mol 5500 kJ/mol 6910 kJ/mol 8760 kJ/mol 10230 kJ/mol 11800 kJ/mol 15600 kJ/mol 17100 kJ/mol 31270 kJ/mol

Electron configuration Shorthand configuration	[Kr] 5s2
Electron configuration Full configuration	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s2
Electron configuration chart	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s2
Electrons per shell	2, 8, 18, 8, 2
Valence electrons	2
Valency electrons	2
Bohr model	Figure: Shell diagram of Strontium (Sr) atom.
Orbital Diagram	1s 2s 2p 3s 3p 3d 4s 4p 5s

Discovery	William Cruickshank (1787)
First isolation	Humphry Davy (1808)
Named by	Humphry Davy (1808)
Discovery of strontium Both strontium and strontianite are named after Strontian, a village in Scotland near which the mineral was discovered in 1790 by Adair Crawford and William Cruickshank; it was identified as a new element the next year from its crimson-red flame test color. The element was eventually isolated by Sir Humphry Davy in 1808 by the electrolysis of a mixture containing strontium chloride and mercuric oxide, and announced by him in a lecture to the Royal Society on 30 June 1808. In keeping with the naming of the other alkaline earths, he changed the name to strontium.

Original word	Strontian
Language of origin	English
Name source	Place
Meaning	“Strontian village”
Country	United Kingdom
Naming The name is derived from Strontian, a small town in Scotland where the metal was first discovered in 1790.

CAS Number	7440-24-6
ChemSpider ID	4514263
EC number	231-133-4
PubChem CID Number	5359327