Here's a breakdown:
* Polarity: Molecules with uneven distribution of electron density are called polar molecules. This uneven distribution creates a separation of charge, with one end being slightly positive and the other end slightly negative.
* Dipole moment: This separation of charge creates a dipole moment, which is a measure of the polarity of the molecule. It is represented by a vector pointing from the negative to the positive center of charge.
Examples of molecules with dipole moments:
* Water (H₂O): The oxygen atom is more electronegative than the hydrogen atoms, pulling electrons closer to itself. This creates a partial negative charge on the oxygen and partial positive charges on the hydrogen atoms.
* Hydrogen chloride (HCl): Chlorine is more electronegative than hydrogen, creating a dipole moment.
Key takeaway: A dipole moment signifies that a molecule has a positive and negative end due to an uneven distribution of electron density.
