A medium can be anything that a wave can pass through e.g the medium can be solid objects, air, water, etc.
Answer:
An engine that creates ignites fuel with highly compressed air.
Answer: Gas
Explanation:
since the gas molecules arent being forcefully bonded together like a solid would be, and liquids tend to have lower kinetic energy than solids
Answer:
Temporary in nature.
No new substance is formed.
Explanation:
Temporary in nature: Does not affect the internal structure of a substance, only the molecules are rearranged.
No new substance is formed: Most of the physical changes are reversible. We can obtain the substance back even after the change.
hope this helps
have an awesome day -TJ