Isotopes are different forms of the same element. They change only in the number of neutrons.

Here's a simple breakdown:

• Protons: Protons are what make an element unique. They tell us what the element is. For example, carbon has 6 protons. This is what we call the atomic number.

• Neutrons: Isotopes of an element have the same number of protons but may have different numbers of neutrons. For instance, regular carbon, known as carbon-12, has 6 neutrons. However, another form, called carbon-14, has 8 neutrons.

• Electrons: In a neutral atom, the number of electrons is equal to the number of protons. This keeps the atom balanced and without any charge.

To sum it up, we can identify isotopes using their mass number. The mass number is found by adding the number of protons and neutrons together. We write that like this:

$\text{Mass number} = \text{Protons} + \text{Neutrons}$

For carbon isotopes:

• For carbon-12, we add: $6 + 6 = 12$
• For carbon-14, we add: $6 + 8 = 14$

So, that's how we understand isotopes and how they are different from one another!