Strontium Strontium Strontium is the chemical element with symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to air. Strontium has physical and chemical properties similar to those of its two vertical neighbors in the periodic table, calcium and barium. It occurs naturally mainly in the minerals celestine and strontianite, and is mostly mined from these. While natural strontium is stable, the synthetic Sr isotope is radioactive and is one of the most dangerous components of
Cutlery mustard spoon and lettuce fork. Steel was always used for more utilitarian knives, and pewter was used for some cheaper items, especially spoons. From the nineteenth century, electroplated nickel silver (EPNS) was used as a cheaper substitute for sterling silver. In 1913, the British metallurgist Harry Brearley discovered stainless steel by chance and this metal has come to be the predominant one used in cutlery. An alternative is melchior, corrosion-resistant nickel and copper alloy, which can also sometimes contain manganese and nickel-iron. Plastic cutlery is made for disposable use, and is frequently used outdoors for camping, excursions, and barbecues for