An isotope of oxygen has mass number 18. Other isotopes of oxygen will have the same

Options

A. Mass number
B. Atomic weight
C. Number of neutrons
D. Number of protons

Explanation

To solve the question, we need to analyze the properties of isotopes of oxygen, particularly focusing on the isotope with a mass number of 18.

### Step-by-Step Solution:

1. **Identify the Isotope**: The given isotope of oxygen is O-18, which has a mass number of 18. This means it has a total of 18 nucleons (protons + neutrons).

2. **Determine the Number of Protons**: All isotopes of an element have the same number of protons. Oxygen has an atomic number of 8, which means it has 8 protons. Therefore, O-18 has 8 protons.

3. **Determine the Number of Neutrons**: The number of neutrons in an isotope can be calculated by subtracting the number of protons from the mass number. For O-18:
- Number of neutrons = Mass number - Number of protons
- Number of neutrons = 18 - 8 = 10 neutrons.

4. **Consider Other Isotopes**: Other isotopes of oxygen, such as O-16, will have different mass numbers but the same number of protons. For example, O-16 has:
- Mass number = 16
- Number of protons = 8
- Number of neutrons = 16 - 8 = 8 neutrons.

5. **Conclusion**: The only property that remains the same across all isotopes of oxygen (including O-18 and O-16) is the number of protons, which is 8.

### Final Answer:
Other isotopes of oxygen will have the same number of protons.