In a water molecule (H_2O), why does the oxygen atom have a partial negative charge while the hydrogen atoms have partial positive charges?

• A. Hydrogen forms a double bond with oxygen, making oxygen negatively charged.
• B. Oxygen is more electronegative than hydrogen, so it attracts the shared electrons more strongly.
• C. Hydrogen has a larger atomic radius than oxygen, causing it to lose electrons to oxygen.
• D. Oxygen donates electrons to hydrogen, resulting in a negative charge on oxygen.

Answer: (B)

Verified step by step guidance

1. Understand the concept of electronegativity, which is the tendency of an atom to attract shared electrons in a chemical bond.
2. Recognize that in a water molecule (H\_2O), oxygen and hydrogen atoms are bonded covalently, meaning they share electrons.
3. Compare the electronegativities of oxygen and hydrogen: oxygen is more electronegative, so it pulls the shared electrons closer to itself.
4. Because the shared electrons spend more time near oxygen, oxygen acquires a partial negative charge (\delta-), while the hydrogens acquire partial positive charges (\delta+).
5. This uneven distribution of electron density creates a polar molecule, explaining why oxygen is partially negative and hydrogens are partially positive in water.