biological molecules

What it is: Electrons in atoms are usually spread out, but they can randomly gather on one side of an atom for a moment.

What happens: This creates a tiny negative charge that can push away other electrons nearby, making the molecules attract each other.

Example: All molecules have this, even nonpolar ones.

What it is: This is a stronger version of dipole interactions, but specifically when hydrogen is bonded to a very electronegative atom like oxygen (O) or nitrogen (N).

What happens: The positive hydrogen and negative atoms pull on each other harder, making the attraction stronger.

Example: Water molecules and the connection between DNA strands.

What it is: In some molecules, electrons aren’t shared equally between atoms, creating partial negative and positive charges.

What happens: Molecules with opposite charges stick together because of attraction.

Example: Water molecules (H₂O) do this.

What it is: When electrons are completely transferred from one atom to another, creating full charges (positive and negative).

What happens: The positive and negative charges attract each other strongly.

Example: Table salt (NaCl) and interactions between parts of proteins.