helium density of catalyst
41X-ray photoelectron spectroscopy — [ right|thumb|350px|Basic components of a monochromatic XPS system.] X ray photoelectron spectroscopy (XPS) is a quantitative spectroscopic technique that measures the elemental composition, empirical formula, chemical state and electronic state… …
42coordination compound — Chem. complex (def. 10). Also called coordination complex. * * * ▪ chemistry Introduction any of a class of substances with chemical structures in which a central metal atom is surrounded by nonmetal atoms or groups of atoms, called ligands… …
43Silicon dioxide — Silica redirects here. For other uses, see Silica (disambiguation). Silicon dioxide …
44Boron nitride — IUPAC name Boron nitride Identifiers …
45Technetium — molybdenum ← technetium → ruthenium Mn ↑ Tc ↓ Re …
46mercury — /merr kyeuh ree/, n., pl. mercuries. 1. Chem. a heavy, silver white, highly toxic metallic element, the only one that is liquid at room temperature; quicksilver: used in barometers, thermometers, pesticides, pharmaceutical preparations,… …
47Antimony — This article is about the element. For the town, see Antimony, Utah. Not to be confused with Antinomy, a type of paradox. tin ← antimony → tellurium As ↑ Sb ↓ Bi …
48Barcode — For the taxonomic method, see DNA barcoding. A UPC A barcode symbol A barcode is an optical machine readable representation of data, which shows data about the object to which it attaches. Originally barcodes represented data by varying the… …
49Electron crystallography — is a method to determine the arrangement of atoms in solids using a transmission electron microscope (TEM). Contents 1 Comparison with X ray crystallography 2 Radiation damage 3 Protein structures determined by electron crystallography …
50Methane — Methane …
