| Ozonkonzentration | ozone concentration |
| Ionenkonzentration | ion concentration |
| Konzentration | concentration |
| Ozongenerator | ozone generator |
| Konkatenation | concatenation |
| Luftionenkonzentration | air ion concentration atmospheric ion concentration |
| Kondensation | condensation |
| Konsekration | dedication |
| Konföderation | confederation |
| Konzelebration | concelebration |
| Konzentrat | concentrate |
| Dokumentation | documentation sign |
| Längenkontraktion | Lorentz contraction length contraction |
| Schwellenkonzentration | threshold concentration |
| Konspiration | conspiracy |
| Konsultation | consultation |
| Rekonziliation | reconciliation |
| Konfiguration | configuration |
| Konfrontation | confrontation |
| Konnotation | connotation |