If bald people work in a restaurant, do they still need to wear a hairnet?
Please help

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

alchemy hadn't scientific methods of study, appeal to mysticism and fantasy, the knowledge of chemistry and physics were modest at that time.

alchemy was - but as new rules were discovered it either changed into chemistry or it became "unscientific".