We use chemical changes in various forms in our daily life. Chemistry is the branch of science which deals with the study of particles around us; it explains the properties of the basic components of particles such as atoms and molecules and the effects of their combination. This chapter covers materials we use every day – soaps, fertilizers, cement, gypsum, Epsom, plaster of paris, phenol and adhesives – their manufacture and uses.
1. Physical and Chemical Changes
| Physical Change | Chemical Change |
|---|---|
| Only the shape, size or volume changes; the state may also change (liquid to gas, liquid to solid) | Results in the change of the substance |
| The substance remains chemically as it is | The original substance is no longer there |
| Cutting a paper into two – both are still paper pieces | Burning a paper – only some ash and smoke are left |