Sugar is a polar substance. This is because sugar molecules are made up of oxygen and hydrogen atoms, which form polar covalent bonds. In a polar covalent bond, the electrons are shared unequally between the atoms, creating a slight positive charge on one end of the molecule and a slight negative charge on the other end.
For example, in a water molecule (H2O), the oxygen atom attracts electrons more strongly than the hydrogen atoms, making the oxygen end slightly negative and the hydrogen ends slightly positive. Similarly, in sugar molecules, the oxygen atoms attract electrons more strongly than the hydrogen atoms, creating a polar molecule.
This polarity allows sugar to dissolve easily in water, which is also a polar substance. The positive and negative ends of the sugar molecules interact with the positive and negative ends of the water molecules, allowing the sugar to dissolve and form a homogeneous solution.