Question

polar covalent bonds result in partial negative and positive charges on the atoms involved; and when partial negative and positive charges occur on different molecules, it can cause them to be attracted to each other or repelled. one particularly common example of this is so important that it has its own name, a hydrogen bond. a hydrogen bond is an attraction between a partial positive charge on a hydrogen atom of one molecule and a partial negative charge on an atom in a different molecule. since oxygen and nitrogen are so common in living organisms, those are almost always the partial negative atoms that participate in hydrogen bonds in the context of biology. the diagram below shows an example of a hydrogen bond. note that by convention, life scientists use dashed lines to indicate hydrogen bonds and solid lines to indicate covalent bonds. which three statements correctly describe the diagram above? select the three best answers. the carbon (c) atom here is shown double - bonded to oxygen (o), so there are four electrons involved. the oxygen atom (o) has a partial negative charge because its higher electronegativity pulls the shared electrons away from the carbon (c) atom. hydrogen bonding occurs when electrons are shared between two atoms, just like a covalent bond. 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. hydrogen bonds, or h - bonds

Explanation:

1. In a double - bond, two pairs of electrons are shared, so 4 electrons are involved in the C=O double - bond.
2. Oxygen is more electronegative than carbon, so it pulls the shared electrons towards itself, resulting in a partial negative charge on oxygen.
3. Nitrogen is more electronegative than hydrogen, so it pulls the shared electrons away from hydrogen, giving hydrogen a partial positive charge. Hydrogen bonding is not the sharing of electrons like in a covalent bond.

Answer:

The carbon (C) atom here is shown double - bonded to oxygen (O), so there are four electrons involved.
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) atom's higher electronegativity pulls the shared electrons away from the hydrogen nucleus.