4. what is meant by the fact that water is a "polar" molecule?
a. water has a slightly negative charge overall
b. water has a slight negative and a slight positive charge at opposite poles
c. water has a very evident charge, but only in a gaseous form
d. water has a slightly positive charge, but only as a liquid

Hello!

A polar molecule is where one of the atoms in a molecule has a slight positive charge, and another has a slight negative charge, due to the unequal sharing of electrons.

Water is one of these molecules - the electrons spend more time around the oxygen atom in the center, and less around the hydrogens, so the hydrogen atoms have a slight positive charge, and the oxygen a slight negative.

Therefore, your answer is B, water has a slight negative and a slight positive charge at opposite poles.

Hope this helps!