Document page
chemistry igcse acapprinted 4 · PDF 4
145 pagesrevision 46934
printed 4 · PDF 4
Page image rendered from the stored file at 110 dpi; it sharpens as you zoom. Outlines are placed from each region’s stored position on the page (612 × 792 pt).
readable
Source of this text: embedded text layer. The better of the embedded text and OCR is kept.
4
(i) States of Matter:
Solids, Liquids, Gases and their Changes of State
• There are 3 states of matter, Solid, Liquid, and Gas:
Process
Type of Reaction
Melting
Endothermic
Boiling/Evaporation
Endothermic
Condensation
Exothermic
Freezing
Exothermic
Sublimation
Endothermic
• Melting, Boiling/Evaporation, and Sublimation are all endothermic reactions as they are
absorbing heat energy to break their bonds.
• Similarly, Freezing and Condensation are exothermic reactions as heat energy is released due to
the formation of their bonds.
• Pure elements/compounds have fixed melting and boiling points, however impure
elements/compounds have a lower melting point, and a higher boiling point, e.g.