Final answer:
Chemists make a distinction between two different types of changes- physical changes and chemical changes.
Step-by-step explanation:
Chemists make a distinction between two different types of changes that they study-physical changes and chemical changes.
Physical changes are changes that do not alter the identity of a substance. They involve a change in the physical state or properties of a substance, such as changes in shape, size, or phase. Examples of physical changes include melting ice, boiling water, and cutting paper. These changes can usually be reversed by simple physical processes.
Chemical changes, on the other hand, are changes that occur when one substance is turned into another substance. During a chemical change, bonds between atoms are broken and new bonds are formed, resulting in the formation of new substances with different properties. Chemical changes are frequently harder to reverse than physical changes. Examples of evidence that indicate a chemical change has occurred include color change, temperature change, light given off, formation of bubbles, formation of a precipitate, etc.