reactive metal
21Water reactive — A water reactive substance is one that spontaneously undergoes a chemical reaction with water. Notable examples include alkali metals sodium through caesium.Water reactive substances are classified as R2 under the UN classification system and as… …
22Deep reactive-ion etching — (DRIE) is a highly anisotropic etch process used to create deep penetration, steep sided holes and trenches in wafers, with aspect ratios of 20:1 or more. It was developed for microelectromechanical systems (MEMS), which require these features,… …
23Precious metal — A precious metal is a rare metallic chemical element of high economic value. Chemically, the precious metals are less reactive than most elements, have high luster, are softer or more ductile, and have higher melting points than other metals.… …
24alkaline-earth metal — /al keuh luyn errth , lin /, Chem. any of the group of bivalent metals including barium, radium, strontium, calcium, and, usually, magnesium, the hydroxides of which are alkalis but less soluble than those of the alkali metals. [1900 05] * * * ▪… …
25Native metal — Kondyor Mine Region Chabarowsk: native platinum nugget A native metal is any metal that is found in its metallic form, either pure or as an alloy, in nature. Metals that can be found as native deposits singly and/or in alloys include aluminium,… …
26Alkaline earth metal — Group 2 Period  2 4 Be 3 …
27Mixed metal oxide — (MMO) electrodes are devices with useful properties for chemical electrolysis. The term refers to a mixture of platinum group metals used to form the surface of the electrode, which provides efficient electrolytic action while resisting corrosion …
28alkali metal — noun Any of the soft, light, reactive metals of Group 1 of the periodic table; lithium, sodium, potassium, rubidium, cesium, and francium. See Also: alkaline earth metal …
29alkali metal — n. Chem. any of the six highly reactive metals in group IA of the periodic table including, in increasing order of reactivity, lithium, sodium, potassium, rubidium, cesium, and francium: see the periodic table of elements in the Reference… …
30alkaline-earth metal — [al′kə lin΄ʉrth′, al′kə līn΄ʉrth′] n. any of the six highly reactive chemical elements in group IIA of the periodic table including, in order of increasing reactivity, beryllium, magnesium, calcium, strontium, barium, and radium: an oxide of any… …
