Lecture : PARTICULATE_NATURE_OF_MATTER
Document Summary
Matter exists in three states: solids, liquids and gases. Matter can be changed in various ways which includes physical, chemical and nuclear changes: physical changes they are normally reversible and no new substances formed. Examples are; (i) change of state such as melting and vaporization (ii) thermal expansion due to heating (iii) dissolving solids in liquids (iv) magnetizing (v) charging electrically: chemical changes they are irreversible and new substances are formed. As this happens they change into other substances. Matter is made up of millions of tiny particles which cannot be seen with naked eyes. These particles are called atoms and are made up of sub -atomic particles called protons, neutrons and electrons. Particles move from one region to another by the process of diffusion. Diffusion is the movement of molecules from regions of high concentration to regions of low concentration until an equilibrium is reached or achieved.
