What is a polar molecule which has a slighty negative charge near the element?

Water is a common example of a polar molecule. A molecule is polar when the electrons tend to spend more time around one area than others. This happens when atoms on one side of the molecule are more electronegative than the others. (Atoms that are higher and farther to the right on the Periodic Table are more electronegative.)

Water is polar because both hydrogens are on one side of the oxygen, and hydrogen is more electronegative than oxygen. Because of this, the hydrogen side is partially negative, while the oxygen side is partially positive.