Question

which three statements correctly describe the diagram above? select the three best answers.
the oxygen atom (o) has a partial negative charge because its higher electronegativity pulls the shared electrons away from the carbon (c) atom.
the hydrogen atom (h) has a partial positive charge because the nitrogen (n) atoms higher electronegativity pulls the shared electrons away from the hydrogen nucleus.
the carbon (c) atom here is shown double - bonded to oxygen (o), so there are four electrons involved.
hydrogen bonding occurs when electrons are shared between two atoms, just like a covalent bond.

Explanation:

1. In a polar - covalent bond like in the given molecule, oxygen is more electronegative than carbon and hydrogen. The oxygen atom has a partial negative charge because its higher electronegativity pulls the shared electrons away from the carbon atom.
2. Hydrogen has a partial positive charge in the molecule due to the electronegativity difference with other atoms (in this case oxygen and carbon). Here, the hydrogen atom has a partial positive charge because the oxygen's higher electronegativity pulls the shared electrons away from the hydrogen nucleus.
3. There is no hydrogen - bonding shown in the diagram. Hydrogen - bonding occurs between a hydrogen atom bonded to a highly electronegative atom (N, O, F) and another highly electronegative atom. Also, the carbon - oxygen double bond has two pairs of shared electrons (4 electrons).

Answer:

• The oxygen atom (O) has a partial negative charge because its higher electronegativity pulls the shared electrons away from the carbon (C) atom.
• The hydrogen atom (H) has a partial positive charge because the oxygen (O) atom's higher electronegativity pulls the shared electrons away from the hydrogen nucleus.
• The carbon (C) atom here is shown double - bonded to oxygen (O), so there are four electrons involved.