# Calculating the Mass Number of an Atom with 5 Protons and 7 Neutrons

Calculating the Mass Number of an Atom with 5 Protons and 7 Neutrons

Have you ever wondered how scientists calculate the mass number of an atom? Well, wonder no more! In this post, we’ll look at a simple example of how to calculate the mass number of an atom with 5 protons and 7 neutrons.

First, let’s define what we mean by “mass number.” The mass number of an atom is simply the total number of protons and neutrons in the nucleus of that atom. This number is important because it helps us identify the specific type of element we’re dealing with.

So, back to our example: we have an atom with 5 protons and 7 neutrons. To calculate the mass number, we simply add these two numbers together:

Mass Number = Number of Protons + Number of Neutrons

In this case, our equation looks like this:

Mass Number = 5 + 7
Mass Number = 12

Therefore, the mass number of our atom with 5 protons and 7 neutrons is 12. Easy, right?

It’s worth noting that while the mass number gives us a good idea of the overall mass of an atom, it doesn’t tell us anything about the number of electrons orbiting the nucleus. That information is given by the atomic number, which is simply the number of protons in the nucleus. So, for our atom with 5 protons, the atomic number would be 5.

In summary, calculating the mass number of an atom is a simple matter of adding up the number of protons and neutrons in its nucleus. By doing so, we can identify the element we’re dealing with and get a better understanding of its properties.