The form of oxygen that combines three oxygen atoms into each molecule is called _____.

• A. peroxide
• B. oxide
• C. dioxygen
• D. ozone

Answer: (D)

Verified step by step guidance

1. Understand that oxygen can exist in different molecular forms, each with a specific number of oxygen atoms bonded together.
2. Recall that the most common form of oxygen we breathe is dioxygen, which consists of two oxygen atoms (O\_2) bonded together.
3. Recognize that when three oxygen atoms combine to form a molecule, this form is called ozone, represented chemically as O\_3.
4. Note that peroxide refers to compounds containing the O\_2\^{2-} ion, not a molecule of three oxygen atoms bonded together.
5. Therefore, the form of oxygen with three oxygen atoms per molecule is ozone.