1. Understand the Basics

* Atomic Number (Z): This is the number of protons in an atom's nucleus. It defines the element. You can find it on the periodic table.

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

* Neutrons: These are neutral particles found in the nucleus.

2. The Formula

To calculate the number of neutrons, use this formula:

Number of Neutrons (N) = Mass Number (A) - Atomic Number (Z)

3. Example

Let's take the example of carbon:

* Carbon's Atomic Number (Z) = 6 (meaning it has 6 protons)

* Carbon's Mass Number (A) = 12 (meaning it has 12 protons and neutrons combined)

Calculation:

* Number of Neutrons (N) = 12 - 6 = 6

Therefore, a carbon atom has 6 neutrons.

Important Note:

* This calculation gives you the number of neutrons in the most common isotope of an element. Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.

* To find the number of neutrons in a specific isotope, you'll need to know the isotope's mass number.