What are the partial charges present on an atom?

Partial charges refer to the uneven distribution of electrons around an atom, resulting in regions of slight positive or negative charge. These charges arise due to differences in electronegativity between atoms in a molecule or compound.

When atoms participate in covalent bonds, the shared electrons are not always equally shared between the atoms. If one atom has a higher electronegativity (ability to attract electrons) than the other, it will pull the shared electrons closer to itself, creating a partial negative charge (δ-) on that atom and a partial positive charge (δ+) on the other atom.

For example, in a molecule like water (H2O), oxygen (O) is more electronegative than hydrogen (H). As a result, the oxygen atom pulls the shared electrons closer to itself, acquiring a partial negative charge (δ-), while the hydrogen atoms acquire partial positive charges (δ+).

These partial charges are denoted by the Greek letter delta (δ) to signify that they are not full charges but rather partial charges resulting from the unequal sharing of electrons in covalent bonds.