Covalent Bonds, Polarity, and Hydrogen Bonding

Vocabulary flashcards covering topics on electron sharing, double bonds, polarity, selfish atoms, hydrogen bonding, and phase changes from the lecture transcript.

Double bond

A chemical bond in which four electrons (two pairs) are shared between two atoms, denoted by two lines and stronger than a single bond.

Polarity

The condition in a covalently bound molecule where there is an unequal distribution of electrons, despite the overall molecule remaining electrically neutral.

Selfish atoms

Atoms in biological macromolecules—specifically oxygen, nitrogen, and phosphorus—that tend to keep shared electrons closer to their own nuclei.

Electronegative

Describing an atom whose nucleus pulls shared electrons closer to itself, giving that atom a slight negative charge (such as oxygen in a water molecule).

Electropositive

Describing an atom whose shared electrons are pulled farther away from its nucleus, giving that atom a slight positive charge (such as hydrogen in a water molecule).

Hydrogen bonds

Interactions formed when an electronegative portion of one molecule is attracted to an electropositive portion (such as hydrogen) of another molecule.

Cohesive

The state of molecules sticking closely together due to intermolecular interactions such as hydrogen bonds, which allows liquids like water to form.

Boiling water

The physical process that breaks the weaker hydrogen bonds between water molecules, allowing them to disperse into steam while leaving the stronger internal covalent bonds intact.