When one atom contributes both bonding electrons in a single covalent bond, the bond is called

A coordinate covalent bond is a type of covalent bond in which the shared electron pair comes from only one of the atoms. While the polar covalent bond is a type of covalent bond between atoms of significantly different electronegativities

Based on this:
When one atom contributes both bonding electrons in a single covalent bond, the bond is called coordinate covalent bond.

While unproven, it uses facts to support part of a conclusion. it is still factual and has predictive power, however.

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