I need a little assistance. Can you help?
The question which seems to be simple enough is
What is a physical change? My son answered -
A physical change is any change that alters the form or appearance of matter into a different substance.
I do not agree. He is missing something. I would answer - A physical change is any change that alters the form or appearance of matter but does not make any substance in the matter into a different substance. What do you think his teacher would say is correct?