CHANGES OF THE MATTER
Changes of matter are common and popular. Changes occur when digested food, burning letters, mprchct pen, etc. As the properties of matter, changes of matter are classified into two ktegori: physical and chemical. Physical change is a process in which substances change the physical form but not its chemical composition. During physical change never formed a new substance. Aggregate state change is the most common type of physical change, melting, building, evaporation, condensation, are all status changes. In each of these processes, substances only changed form, and composition of the substance remains the same. Chemical change is a process in which the substance is altered in its chemical composition. Chemical changes always include conversion of the substance in a ose..më many new substances which have different properties and composition of the properties of the original substance. For example, objects of iron rust if left to stand in moist air.
