Cambridge IGCSE Chemistry · Syllabus 0620 · Atoms, Elements and Compounds
Compound
What is Compound?
A substance in which atoms of two or more different elements are chemically bonded together in a fixed ratio. The chemical properties of a compound are completely different from those of the elements that formed it, and it can only be separated back into those elements by a chemical reaction, not by a physical method.
This definition is part of the Atoms, Elements and Compounds chapter in Cambridge IGCSE Chemistry.
Common mistakes with Compound
- 8. “Anything with a lattice structure conducts electricity.” Core 2.4.4 Repair Conduction needs a mobile charged particle. An ionic lattice has ions that are fixed until it is molten or dissolved, which is why an ionic compound conducts only in those two states. Diamond has neither ions nor delocalised electrons, so it does not conduct at all. The ionic half is taught fully in Lesson 2.4C. Supplement — Extended candidates Supplement 2.7.2 The metallic case completes the set: a metallic lattice has mobile delocalised electrons, so a metal conducts even as a solid. Taught fully in Lesson 2.7.