Strontium
Definition and meaning of Strontium in chemistry.
Strontium is an alkaline earth metal chemical element with the symbol Sr and atomic number 38. It is a highly reactive, silvery-white metallic element that quickly develops a yellowish tint when exposed to the atmosphere.
In more detail
Located squarely in group 2 of the periodic table, strontium exhibits physical and chemical properties highly similar to its vertical neighbors, calcium and barium. It is physically softer than calcium and demonstrates an even greater reactivity in water, vigorously producing strontium hydroxide and hydrogen gas upon contact. Upon immediate exposure to oxygen in the air, the pure metal rapidly oxidizes to form a dark, dull protective layer of strontium oxide, necessitating its careful storage under protective mineral oil. Strontium occurs naturally and abundantly in the sulfate mineral celestine and the carbonate mineral strontianite. It readily forms a highly stable Sr2+ cation in its salts, which famously burn with a brilliant, intense red color in pyrotechnic flame tests.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Sr |
| Atomic number | 38 |
| Atomic mass | 87.62 u |
| Category | Alkaline Earth Metal |
| State at room temperature | Solid |
| Melting point | 777 degrees Celsius |
| Boiling point | 1377 degrees Celsius |
| Discoverer | Adair Crawford (1790) |
Because of its brilliant crimson flame, strontium salts like strontium carbonate are widely and exclusively used in the manufacture of fireworks, road flares, and emergency signaling devices to produce a deep red visual effect.
Frequently asked questions
What exactly is the infamous isotope strontium-90?
Strontium-90 is a highly dangerous, synthetic radioactive isotope produced by nuclear fission and atomic fallout that poses a severe health risk because the human body absorbs it into bones instead of calcium.
Is natural, stable strontium safe for humans to handle?
While the pure metallic form is highly chemically reactive and must be handled carefully to avoid chemical burns, stable strontium compounds are generally considered to have very low toxicity for humans.