atomic hydrogen welding
41radiation — radiational, adj. /ray dee ay sheuhn/, n. 1. Physics. a. the process in which energy is emitted as particles or waves. b. the complete process in which energy is emitted by one body, transmitted through an intervening medium or space, and… …
42Helium — otherusesHelium (He) is a colorless, odorless, tasteless, non toxic, inert monatomic chemical element that heads the noble gas group in the periodic table and whose atomic number is 2. Its boiling and melting points are the lowest among the… …
43Noble gas — Group 18 Period 1 2 He 2 …
44Copper — For other uses, see Copper (disambiguation) …
45Period 1 element — A period 1 element is one of the chemical elements in the first row (or period) of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the… …
46metallurgy — metallurgic, metallurgical, adj. metallurgically, adv. metallurgist /met l err jist/ or, esp. Brit., /meuh tal euhr jist/, n. /met l err jee/ or, esp. Brit., /meuh tal euhr jee/, n. 1. the technique or science of working or heating metals so as… …
47Niobium — zirconium ← niobium → molybdenum V ↑ Nb ↓ Ta …
48Mathematics 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… …
49chemical compound — Introduction any substance composed of identical molecules consisting of atoms (atom) of two or more chemical elements (chemical element). All the matter in the universe is composed of the atoms of more than 100 different chemical elements …
50List of Russian people — The Millennium of Russia monument in Veliky Novgorod, featuring the statues and reliefs of the most celebrated people in the first 1000 years of Russian history …
