A chemical change affects on the molecular level of matter, which makes it irreversible. Combustion is a pretty good exmple. Physical changes are reversible and dont alter the formula. Hope this helped!
Burning splint test
2H2 (g) + O2 (g) -> 2H20 (g) + heat
It’s a combustion reaction
What is the exoeruent. Searched it up on google and only came up with two search results. None related to chemistry
