| Kernreaktion | nuclear reaction |
| Kernreaktor | nuclear reactor |
| Gegenreaktion | counterreaction |
| Kettenreaktion | chain reaction |
| Überreaktion | overreaction |
| Kreation | creation |
| Abreaktion | abreaction |
| Reaktion | reaction |
| Redoxreaktion | redox reaction |
| Extraktion | extraction |
| Kontraktion | contraction |
| Erektion | erection |
| Konfektion | make manufacture ready-to-wear off-the-peg clothing off-the-rack clothing clothing industry |
| Perfektion | perfection |
| Reinfektion | reinfection |
| Korrelation | correlation association |
| Kerninflation | core inflation |
| Keratin | keratin |
| Kernfission | nuclear fission |
| Kernfusion | nuclear fusion |