Oxygen has three isotopes with mass numbers of 16 17
and 18
The atomic number of oxygen is eight. How many protons and neutrons does each of the isotopes have?
The Correct Answer and Explanation is:
Oxygen has three isotopes, each with a different mass number: 16, 17, and 18. The atomic number of oxygen is 8, which means it has 8 protons in all of its isotopes, as the atomic number defines the number of protons in an element.
The mass number of an isotope is the total number of protons and neutrons in its nucleus. To calculate the number of neutrons in an isotope, you subtract the number of protons from the mass number:
- Oxygen-16:
- Mass number = 16
- Number of protons = 8 (since oxygen’s atomic number is 8)
- Number of neutrons = Mass number – Number of protons = 16 – 8 = 8 neutrons
- Therefore, Oxygen-16 has 8 protons and 8 neutrons.
- Oxygen-17:
- Mass number = 17
- Number of protons = 8
- Number of neutrons = Mass number – Number of protons = 17 – 8 = 9 neutrons
- Therefore, Oxygen-17 has 8 protons and 9 neutrons.
- Oxygen-18:
- Mass number = 18
- Number of protons = 8
- Number of neutrons = Mass number – Number of protons = 18 – 8 = 10 neutrons
- Therefore, Oxygen-18 has 8 protons and 10 neutrons.
Summary of Isotopes:
- Oxygen-16: 8 protons, 8 neutrons
- Oxygen-17: 8 protons, 9 neutrons
- Oxygen-18: 8 protons, 10 neutrons
These variations in the number of neutrons give each isotope a different mass number, even though they all have the same number of protons, which is characteristic of oxygen. The isotopes of oxygen are important in various applications, such as in determining the age of water samples using oxygen isotopes or understanding biological and environmental processes.
