Fluorine has an atomic number of 9 and an atomic mass of 19. How many neutrons are present in a typical atom of fluorine?

• A. 9
• B. 28
• C. 19
• D. 10

Answer: (D)

Verified step by step guidance

1. Identify the atomic number (Z) of fluorine, which is given as 9. The atomic number represents the number of protons in the nucleus of the atom.
2. Identify the atomic mass (A) of fluorine, which is given as 19. The atomic mass is approximately the total number of protons and neutrons in the nucleus.
3. Recall the relationship between atomic mass, protons, and neutrons: \(A = Z + N\), where \(N\) is the number of neutrons.
4. Rearrange the formula to solve for the number of neutrons: \(N = A - Z\).
5. Substitute the known values into the equation: \(N = 19 - 9\), which will give the number of neutrons in a typical fluorine atom.