Which of the following best explains why water is considered a polar molecule?

• A. Water is composed of identical atoms, making it nonpolar.
• B. Water contains ionic bonds between hydrogen and oxygen atoms.
• C. Water has an uneven distribution of electron density due to the difference in electronegativity between hydrogen and oxygen, resulting in a partial positive and partial negative end.
• D. Water molecules are linear, causing the charges to be evenly distributed.

Answer: (C)

Verified step by step guidance

1. Understand the concept of molecular polarity: A molecule is polar if it has an uneven distribution of electron density, leading to partial positive and negative charges on different parts of the molecule.
2. Recognize that water (H\_2O) consists of two hydrogen atoms and one oxygen atom bonded together, but these atoms are not identical, so the molecule is not composed of identical atoms.
3. Recall that the bonds in water are covalent, not ionic, meaning electrons are shared rather than transferred between atoms.
4. Consider the difference in electronegativity between oxygen and hydrogen: oxygen is more electronegative, so it attracts the shared electrons more strongly, creating a partial negative charge near oxygen and partial positive charges near hydrogens.
5. Note the bent shape of the water molecule (not linear), which prevents the dipole moments from canceling out, resulting in an overall polar molecule with distinct positive and negative ends.