Answer
Physical changes: Iodine vaporized; cooling of violet vapor of iodine to yield pure solid; solid iodine and zinc metal powder were mixed
Chemical changes: solid iodine and zinc metal powder were ignited to give a white powder
Work Step by Step
Physical changes: Iodine was vaporized when it is heated to give the violet vapor of iodine. This is a physical change because iodine changes its form of the matter from solid to gas, but it retains its chemical identity as it is still iodine.
When iodine vapor is cooled it changes its form from gas to pure solid iodine. This is a physical change as iodine retains its chemical identity as it is still iodine in two different form of matter: gas ( or iodine vapor) at the beginning of the process and solid iodine at the end of the process.
Mixing of solid iodine and zinc powder at room temperature is a physical process as iodine and zinc retain their individual chemical identity.
Chemical changes: When we heat the mixture of iodine with zinc, a chemical reaction happens between the two substances iodine and zinc. As a result, it is formed a new substance described as white powder. As iodine and zinc didn’t retain their individual chemical identity when the mixture was heated, a chemical change has happened.
