helium density of catalyst
21Cerium — lanthanum ← cerium → praseodymium ↑ Ce ↓ Th …
22Platinum — This article is about the chemical element. For other uses, see Platinum (disambiguation). iridium ← platinum → gold Pd ↑ Pt ↓ Ds …
23gas — gasless, adj. /gas/, n., pl. gases, v., gassed, gassing. n. 1. Physics. a substance possessing perfect molecular mobility and the property of indefinite expansion, as opposed to a solid or liquid. 2. any such fluid or mixture of fluids. 3. any… …
24rare-earth element — /rair errth /, Chem. any of a group of closely related metallic elements, comprising the lanthanides, scandium, and yttrium, that are chemically similar by virtue of having the same number of valence electrons. Also called rare earth metal. [1955 …
25Molybdenum — niobium ← molybdenum → technetium Cr ↑ Mo ↓ W …
26Cold fusion — This article is about the Fleischmann–Pons claims of nuclear fusion at room temperature. For the original use of the term cold fusion , see Muon catalyzed fusion. For all other definitions, see Cold fusion (disambiguation). Diagram of an open… …
27Iron — Fe redirects here. For other uses, see Fe (disambiguation). This article is about the chemical element. For other uses, see Iron (disambiguation). manganese …
28Silver — This article is about the chemical element. For the color, see Silver (color). For other uses, see Silver (disambiguation). palladium ← silver → cadmium …
29Samarium — promethium ← samarium → europium ↑ Sm ↓ …
30Sulfur — This article is about the chemical element. For other uses, see Sulfur (disambiguation). phosphorus ← sulfur → chlorine …
