boiling period
21Chemical element — The periodic table of the chemical elements A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus.[1] Familiar examples of …
22hydrocarbon — hydrocarbonaceous, adj. /huy dreuh kahr beuhn, huy dreuh kahr /, n. any of a class of compounds containing only hydrogen and carbon, as an alkane, methane, CH4, an alkene, ethylene, C2H4, an alkyne, acetylene, C2H2, or an aromatic compound,… …
23nitrogen group element — ▪ chemical elements Introduction any of the chemical elements that constitute Group Va of the periodic table (see Figure >). The group consists of nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi). The elements share… …
24Alkaline earth metal — Group 2 Period  2 4 Be 3 …
25Portable water purification — devices – also known as point of use (POU) water treatment systems and field water disinfection techniques – are self contained units that can be used by recreational enthusiasts, military personnel, survivalists, and others who must… …
26petroleum refining — Introduction conversion of crude oil into useful products. History Distillation of kerosene and naphtha The refining of crude petroleum owes its origin to the successful drilling of the first oil well in Titusville, Pa., in 1859. Prior to… …
27Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
28Gordon Ramsay — Not to be confused with Gordon Ramsey. Gordon Ramsay Gordon Ramsay, 2010 Born Gordon James Ramsay 8 November 1966 (1966 11 08) (age 45) Johnstone, Renfrewshire …
29distilled spirit — ▪ alcoholic beverage Introduction also called distilled liquor, alcoholic beverage (such as brandy, whisky, rum, or arrack) that is obtained by distillation from wine or other fermented fruit or plant juice or from a starchy material (such as …
30Francium — radon ← francium → radium Cs ↑ Fr ↓ Uue …
