How many oxygen atoms are present in a single molecule of water (H_2O)?

• A. 0
• B. 1
• C. 3
• D. 2

Answer: (B)

Verified step by step guidance

1. Identify the chemical formula of the molecule given, which is H_2O for water.
2. Understand that the subscript number in a chemical formula indicates the number of atoms of that element in one molecule.
3. Look at the subscript next to oxygen (O) in H_2O. Since there is no subscript explicitly written after O, it means there is exactly 1 oxygen atom.
4. Recognize that the subscript 2 after H means there are 2 hydrogen atoms, but this does not affect the count of oxygen atoms.
5. Conclude that a single molecule of water contains 1 oxygen atom.