Isotopes: There are 20 known isotopes of strontium, 4 stable and 16 unstable. Natural strontium is a mixture of the 4 stable isotopes. Properties: Strontium is softer than calcium and decomposes more vigorously in water. Finely divided strontium metal ignites spontaneously in air. Strontium is a silvery metal, but it rapidly oxidizes to a yellowish color. Because of its propensity for oxidation and ignition, strontium is typically stored under kerosene. Strontium salts color flames crimson and are used in fireworks and flares. Uses: Strontium-90 is used in Systems for Nuclear Auxilliary Power (SNAP) devices. Strontium is used in producing glass for color television picture tubes.
In contrast, a SKU, or Stock Keeping Unit, is a number assigned to a product by the company for stock-keeping purposes and internal operations. The UPC code is affixed to a product wherever it is sold, remaining a constant throughout the productâs shelf life.
An inertial measurement unit (IMU) is an electronic device that measures and reports a craftâs velocity, orientation, and gravitational forces, using a combination of accelerometers andgyroscopes, sometimes also magnetometers.