The partial negative charge in a molecule of water occurs because the electrons shared between the oxygen and hydrogen stoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus?

True

Explanation:

Partial charge is due to difference in electron negativity between two atoms in a molecule. Electrons are attracted towards the atoms with more electro-negativity. In water molecule oxygen has more electro-negativity as compared to oxygen so it is more attracted towards oxygen and thus there is partial charge on it.

b) mutualism

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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".