Strontium was discovered in 1790 by Adair Crawford and William Cruickshank, who identified a new mineral (strontianite) in lead mines near the Scottish village of Strontian.
They realized that this mineral contained a new element that was different from barium, though it exhibited similar properties. The element was isolated in its metallic form by Sir Humphry Davy in 1808 using electrolysis, following his successful isolation of potassium and sodium.
QUICK REFERENCE
- Symbol: Sr
- Atomic Number: 38
- Atomic Weight: 87.62
- Element Classification: Alkaline Earth Metal
- Discovered By: Adair Crawford and William Cruickshank
- Discovery Date: 1790
- Name Origin: From Strontian, a village in Scotland
- Density(g/cc): 2.64
- Melting Point: 777°C
- Boiling Point: 1377°C
- Appearance: Silvery-white, soft metal
- Atomic Radius(pm): 215
Relation to Other Elements
Strontium is an alkaline earth metal, part of group 2 of the periodic table, which includes beryllium, magnesium, calcium, barium, and radium. These metals are characterized by their two electrons in the outer shell, leading them to typically form +2 cations. Strontium shares many properties with other members of its group, such as reactivity with water (though to a lesser extent than calcium) and the ability to form stable compounds with a variety of anions. Strontium’s compounds often exhibit a red flame color, a property utilized in fireworks and flares.
Natural Occurrence
Strontium is the 15th most abundant element in the Earth’s crust, found in minerals such as strontianite (SrCO₃) and celestite (SrSO₄). It is not found in nature in its elemental form due to its reactivity. Strontium minerals are mined in several countries, including Mexico, Spain, and China. Strontium is also present in trace amounts in seawater and certain foods.
Uses
Strontium has a variety of applications:
- Fireworks and Flares: Strontium salts, particularly strontium carbonate (SrCO₃) and strontium nitrate (Sr(NO₃)₂), are used to impart a bright red color to fireworks and signal flares.
- Alloys: Strontium can be alloyed with aluminum, making the aluminum casting process easier and improving the properties of the finished product.
- Medical: The radioactive isotope strontium-89 is used in the treatment of bone cancer to relieve pain. Strontium ranelate was used to treat osteoporosis, though its use has been limited due to concerns about its risk-to-benefit ratio.
- Ferrite Magnets: Strontium can be used to produce ferrite magnets, which are common in small electric motors, loudspeakers, and various electronic devices.
- Glass Manufacturing: Strontium oxide (SrO) is used in glass for color television cathode ray tubes to block X-ray emissions and in other types of special glass.
The discovery of strontium expanded the understanding of alkaline earth metals and their chemistry. While strontium’s uses in pyrotechnics and medical treatments are perhaps the most well-known, its applications in manufacturing and technology demonstrate the versatility and importance of this element.