Question

lesson 42 - classification of materials
why is this a physical change?
(1 point)
it changes form
same gas before and
after
it makes a mess
its not, its a chemical
change

Explanation:

A physical change involves a change in form or state without altering the chemical composition. If the gas is the same before and after, it indicates no new substance is formed, which is a key characteristic of a physical change. Changing form could also be a physical change, but if it's a gas - to - gas transformation (same gas), it's a more precise indicator. Making a mess is not a scientific criterion for physical change. And if it were a chemical change, a new substance would be formed.

Answer:

same gas before and after