inertness
21Helium — 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… …
22Platinum — This article is about the chemical element. For other uses, see Platinum (disambiguation). iridium ← platinum → gold Pd ↑ Pt ↓ Ds …
23Titanium — This article is about the chemical element. For other uses, see Titanium (disambiguation). scandium ← titanium → vanadium …
24Gutta-percha — Taxobox name = Gutta percha image width = 240px image caption = Palaquium gutta regnum = Plantae divisio = Magnoliophyta classis = Magnoliopsida ordo = Ericales familia = Sapotaceae genus = Palaquium genus authority = Blanco subdivision ranks =… …
25Sand casting — Sand casting, also known as sand molded casting, is a metal casting process characterized by using sand as the mold material. It is relatively cheap and sufficiently refractory even for steel foundry use. A suitable bonding agent (usually clay)… …
26lubrication — See lubricate. * * * Introduction of any of various substances between sliding surfaces to reduce wear and friction. Lubricants may secondarily control corrosion, regulate temperature, electrically insulate, remove contaminants, or damp shock.… …
27argon — /ahr gon/, n. Chem. a colorless, odorless, chemically inactive, monatomic, gaseous element that, because of its inertness, is used for filling fluorescent and incandescent lamps and vacuum tubes. Symbol: Ar; at. no.: 18; at. wt.: 39.948. [1890… …
28nitrogen — /nuy treuh jeuhn/, n. Chem. a colorless, odorless, gaseous element that constitutes about four fifths of the volume of the atmosphere and is present in combined form in animal and vegetable tissues, esp. in proteins: used chiefly in the… …
29refractory — refractorily, adv. refractoriness, n. /ri frak teuh ree/, adj., n., pl. refractories. adj. 1. hard or impossible to manage; stubbornly disobedient: a refractory child. 2. resisting ordinary methods of treatment. 3. difficult to fuse, reduce, or… …
30Mathematics 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… …
