alkaline-earth element
121Nuclear fission — For the generation of electrical power by fission, see Nuclear power. Splitting the atom redirects here. For the EP, see Splitting the Atom. Nuclear physics Radioactive decay Nuclear fission Nuclear fusio …
122lutetium — /looh tee shee euhm/, n. Chem. a trivalent rare earth element. Symbol: Lu; at. wt.: 174.97; at. no.: 71. Also, lutecium. [1905 10; < L Lutet(ia) Paris + IUM] * * * ▪ chemical element (Lu), chemical element, rare earth metal of the lanthanoid… …
123lithium — /lith ee euhm/, n. 1. Chem. a soft, silver white metallic element, the lightest of all metals, occurring combined in certain minerals. Symbol: Li; at. wt.: 6.939; at. no.: 3; sp. gr.: 0.53 at 20°C. 2. Pharm. the substance in its carbonate or… …
124History of the periodic table — The history of the periodic table reflects over a century of growth in the understanding of chemical properties, and culminates with the publication of the first actual periodic table by Dmitri Mendeleev in 1869.[1] While Mendeleev built upon… …
125Group (periodic table) — The periodic table of the chemical elements. The columns represent the groups In chemistry, a group (also known as a family) is a vertical column in the periodic table of the chemical elements. There are 18 groups in the standard periodic table,… …
126Nonmetal — Nonmetal, or non metal, is a term used in chemistry when classifying the chemical elements. On the basis of their general physical and chemical properties, every element in the periodic table can be termed either a metal or a nonmetal. (A few… …
127cerium — /sear ee euhm/, n. a steel gray, ductile metallic element of the rare earth group found only in combination. Symbol: Ce; at. wt.: 140.12; at. no.: 58. [1795 1805; CER(ES) + IUM] * * * Chemical element, a rare earth metal of the lanthanide series… …
128oxidation–reduction reaction — ▪ chemical reaction Introduction also called redox reaction any chemical reaction in which the oxidation number of a participating chemical species changes. The term covers a large and diverse body of processes. Many oxidation– reduction… …
