Question

How do we find the number of neutrons in an atom?

Answer 1

To find the number of neutrons in an atom, you can use the following formula:

\[
\text{Number of Neutrons} = \text{Atomic Mass Number} - \text{Atomic Number}
\]

Here's what each term means:

- **Atomic Mass Number (A)**: This is the total number of protons and neutrons in the nucleus of an atom. It is typically represented as a whole number and may appear as a superscript to the left of the chemical symbol (e.g., \(^{14}\text{C}\) for carbon-14 where 14 is the atomic mass number).

- **Atomic Number (Z)**: This is the number of protons in the nucleus of an atom, and it defines the element. It is usually represented as a whole number and appears as a subscript to the left of the chemical symbol (e.g., \(_6\text{C}\) for carbon where 6 is the atomic number).

### Example:
Let’s say you want to find the number of neutrons in carbon-12 (symbolized as \(^{12}\text{C}\)).

1. The atomic mass number \(A\) of carbon-12 is 12.
2. The atomic number \(Z\) of carbon is 6 (since carbon has 6 protons).

Now apply the formula:

\[
\text{Number of Neutrons} = 12 - 6 = 6
\]

So, carbon-12 has 6 neutrons.