Strontium 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.
Three reasons Strontium stands out
- 1
Used in fireworks for red color.
- 2
Its radioactive isotope is a significant nuclear fallout product that can substitute for calcium in human bones.
- 3
It was used in cathode-ray televisions to absorb X-rays emitted by the screen and protect viewers.
The crimson signature in a flame
Strontium salts color fireworks and emergency flares a saturated red. Chemically it resembles calcium closely enough that the body may place it in bone; that makes radioactive strontium-90 especially hazardous after nuclear fallout. Stable strontium isotopes, meanwhile, can trace where ancient people and animals lived.