5- pase change
https://docs.google.com/document/d/1u5DlVKwaJ0UzBOA_KNU0PczVN5ufVDAXrquQL-ynO0s/edit?tab=t.0
6- cemicl reaction
https://docs.google.com/document/d/1XtE8lGrbYUQEjfHseV4yVzuBXSPj1eWzRURoTTujfOA/edit?tab=t.0
