HAZMAT Technician Practice Exam 2025 – The All-In-One Resource to Master Your Certification!

Physical changes are processes that alter the form or appearance of a substance without changing its chemical composition. This characteristic allows many physical changes to be reversible, meaning the original substance can be recovered after the change occurs. For instance, when water is frozen into ice, it can be melted back into water, demonstrating the reversible nature of this physical change.

In contrast, the other statements do not accurately reflect the nature of physical changes. They might imply that physical changes involve alterations in chemical structures or that they release energy to a greater extent than chemical changes, neither of which holds true. Understanding the reversible nature of physical changes is essential for properly applying concepts in chemistry and hazardous materials handling.