part per million
121indium — /in dee euhm/, n. Chem. a rare metallic element, soft, white, malleable, and easily fusible, found combined in various ore minerals, esp. sphalerite: so called from the two indigo blue lines in its spectrum. Symbol: In; at. wt.: 114.82; at. no.:… …
122protactinium — /proh tak tin ee euhm/, n. Chem. a radioactive, metallic element. Symbol: Pa; at. no.: 91. Also, protoactinium. [1915 20; PROT + ACTINIUM] * * * ▪ chemical element (Pa), radioactive chemical element of the actinoid series of the periodic… …
123fluoridation of water — Addition of fluoride compounds to water (see fluorine) at one part per million to reduce dental caries (cavities). This practice is based on the lower rates of caries seen in areas with moderate natural fluoridation of water and on studies… …
124platinum group — ▪ chemical element group Introduction six metals, in order of increasing atomic weight, ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), and …
125krypton — One of the noble gases, present in small amounts in the atmosphere (1.14 ppm by dry volume); atomic no. 36, atomic wt. 83.80; 85Kr (half life of 10.73 years) has been used in studies of cardiac abnormalities. [G. kryptos, concealed] * * *… …
126Clive McCay — Born 1898 Died 1967 Institutions Cornell …
127Hanwei Group — 韩伟集团 Type Private Industry Chicken layer farming; egg products manufacturing; seafood aquaculture Founded Dalian, Liaoning Headquarters Dalian, Liaoning …
128sodium silicofluoride — n SODIUM FLUOSILICATE * * * a compound added to water to produce 0.7 to 1 part per million of fluorine, to prevent dental caries, and also used in insecticides. Called also s. fluosilicate …
