Chemical or physical change pls help

9 physical

10 physical

11 physical

12 chemical

13 physical

14 chemical

15 physical

If it does not change the chemical makeup which is shown if it makes a change in color, temp, sound, or produces gas, its just a physical change.

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.