Reversing means to go back. Reversible changes are where a change to something can be undone again. The change is only temporary and the substance can be put back to how it was before. Irreversible ...

Sorry! Anyway, some changes we make to materials are irreversible. So once the change has happened, we can't go back again. If you crack an egg in a frying pan and heat it up, that's an irreversible ...