You can't directly "solve for neutrons" in the same way you solve for an unknown variable in an equation. Neutrons are fundamental particles, not mathematical quantities. However, you can determine the number of neutrons in an atom using a few key pieces of information:

1. Atomic Number (Z): This represents the number of protons in an atom's nucleus.

2. Mass Number (A): This represents the total number of protons and neutrons in an atom's nucleus.

Here's the formula:

Number of neutrons = Mass Number (A) - Atomic Number (Z)

Example:

* Carbon-12 has an atomic number of 6 (meaning 6 protons) and a mass number of 12.

* Number of neutrons = 12 - 6 = 6 neutrons.

Keep in mind:

* You can find the atomic number and mass number of an element on the periodic table.

* Isotopes of the same element have the same number of protons but different numbers of neutrons.

Let me know if you have a specific atom or isotope in mind, and I can help you calculate the number of neutrons!