Question

The structure of water is critical to the properties of water that support life on earth. Water is able to achieve these properties due to the nature of the molecule itself. Which of the following correctly describes the structure of a water molecule?

A. Water is a polar molecule due to the high electronegativity of oxygen, which pulls electrons closer to the oxygen atom

B. Water is a nonpolar molecule due to the high electronegativity of oxygen, which pulls electrons closer to the oxygen atom

C. Water is a polar molecule due to the high electronegativity of hydrogen, which pushes electrons closer to the oxygen atom

D. Water is a nonpolar molecule due to the high electronegativity of hydrogen, which pushes electrons closer to the oxygen atom

Answer 1

A. Water is a polar molecule due to the high electronegativity of oxygen, which pulls electrons closer to the oxygen atom.
H2O is a highly polar liquid that's vital to life on Earth. Let's take a look at the available options and see what is correct.
First off, we can immediately eliminate options B and D since both claim that water is nonpolar and since in reality water is polar, both of those options are wrong, leaving us just options A and C to pick from. The only difference between A and C is one claims that oxygen has high electronegativity and the other claims that hydrogen has high electronegativity. So let's lookup the electonegativity of those elements:
Hydrogen has an electronegativity of 2.2
Oxygen has an electronegativity of 3.44
Looks like oxygen has the higher electronegativity which agrees with option "A" and conflicts with option "C". Therefore option "A" is correct.

Answer 2

Water is a polar substance made of hydrogen and oxygen atoms. Large number of water molecules orient themselves such that the negative side of a molecule is near the positive side of the other. Hydrogen bond form between the relatively positively charged hydrogen atom and the relatively negatively charged oxygen atom of adjacent water molecules.
Therefore; the correct answer is A