Stronțiu
38
Sr
Grupă
2
Perioadă
5
Bloc
s
Protoni
Electroni
Neutroni
38
38
50
Proprietăți Generale
Număr atomic
38
Masă atomică
87,62
Numar de masa
88
Categorie
Metale alcalino-pământoase
Culoare
Argint
Radioactive
Nu
Numit după Strontian, un oraș în Scoția
Structură cristalină
Față Centrată Cubic
Istoric
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.
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.
Electroni pe nivelul de energie
2, 8, 18, 8, 2
Configurație electronică
[Kr] 5s2
Strontium metal turns yellow when exposed to air
Proprietăți Fizice
Fază
Solid
Densitate
2,64 g/cm3
Punct de topire
1050,15 K | 777 °C | 1430,6 °F
Punct de fierbere
1655,15 K | 1382 °C | 2519,6 °F
Energie de fuziune
8 kJ/mol
Energie de evaporare
137 kJ/mol
Căldură specifică
0,301 J/g·K
Abundența în scoarța Pământului
0,036%
Abundența în Univers
4×10-6%
Credite imagine: Wikimedia Commons (Alchemist-hp)
The chemical element strontium as a synthetic made crystals, sealed under argon in a glas ampoule
Numarul CAS
7440-24-6
Număr CID PubChem
5359327
Proprietăți Atomice
Rază atomică
215 pm
Rază de covalență
195 pm
Electronegativitate
0,95 (Scara lui Pauling)
Potențial de ionizare
5,6949 eV
Volum molar
33,7 cm3/mol
Conductivitate termică
0,353 W/cm·K
Număr de oxidare
1, 2
Aplicații
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.
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.
Strontium's non-radioactive isotopes are considered non-toxic
Izotopi
Izotopi stabili
84Sr, 86Sr, 87Sr, 88SrIzotopi instabili
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