|  | C |
SECTION C — CHEMISTRY AND METALLURGY

|  | C |
Note(s) Definitions for Section C: Alkali metals: Li, Na, K, Rb, Cs, Fr Alkaline earth metals: Ca, Sr, Ba, Ra Lanthanides: elements with atomic numbers 57 to 71 inclusive Rare earths: Sc, Y, Lanthanides Actinides: elements with atomic numbers 89 to 103 inclusive Refractory metals: Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W Halogens: F, Cl, Br, I, At Noble gases: He, Ne, Ar, Kr, Xe, Rn Platinum group: Os, Ir, Pt, Ru, Rh, Pd Noble metals: Ag, Au, Platinum group Light metals: alkali metals, alkaline earth metals, Be, Al, Mg Heavy metals: metals other than light metals Iron group: Fe, Co, Ni Non-metals: H, B, C, Si, N, P, O, S, Se, Te, noble gases, halogens Metals: elements other than non-metals Transition elements: elements with atomic numbers 21 to 30 inclusive, 39 to 48 inclusive, 57 to 80 inclusive, 89 upwards

METALLURGY

|  | C25 |
ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR (electrodialysis, electro-osmosis, separation of liquids by electricity Fulltext... Hierarchy... Expanded...B01D; electrolytic machining Fulltext... Hierarchy... Expanded...B23P; electroless, i. e. chemical, plating Fulltext... Hierarchy... Expanded...C23C; anodic or cathodic protection Fulltext... Hierarchy... Expanded...C23F; electrolytic production of single crystals Fulltext... Hierarchy... Expanded...C30B; electrochemical methods of analysis Fulltext... Hierarchy... Expanded...G01N; electrochemical measuring, indicating or recording devices Fulltext... Hierarchy... Expanded...G01R; electrolytic circuit elements, e.g. capacitors, Fulltext... Hierarchy... Expanded...H01G; electrochemical current or voltage generators Fulltext... Hierarchy... Expanded...H01M) [2]

|  | C25 |
Note(s) Inventions dealing with electrolytic or electrophoretic processes and apparatus or operational features are classified (a) under the groups for the compounds or articles produced, and (b) under the groups provided for the apparatus or operational features. [2] The electrolytic or eletrophoretic purification of liquids is classified in the classes appropriate to the nature of the liquid, e.g. Fulltext... Hierarchy... Expanded...A01K 63/00, Fulltext... Hierarchy... Expanded...C02F 1/46, Fulltext... Hierarchy... Expanded...C25B 15/08, Fulltext... Hierarchy... Expanded...C25D 21/16, Fulltext... Hierarchy... Expanded...C25F 7/02. [2]

|  | C25B |
ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR [2]

|  | C25B |
Note(s) In this sub-class, in the absence of an indication to the contrary an invention is classified in the last appropriate place. [2] Compounds are secondarily classified in the appropriate classes, e.g. Fulltext... Hierarchy... Expanded...C01, Fulltext... Hierarchy... Expanded...C07, if of interest. [2]

|  | C25C |
PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR [2]

|  | C25D |
PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING (printed circuits by metal deposition Fulltext... Hierarchy... Expanded...H05K 3/18); APPARATUS THEREFOR [2]

|  | C25F |
PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS [2]

|  | C25F |
Note(s) In this sub-class, an invention is classified in the last appropriate place. [2]