To find the mass number of an atom, you need to know a few important things about how atoms are built. Let’s go through the steps together in a fun and easy way!

Step 1: Learn Important Terms

• Atomic Number ($Z$): This is the number of protons in an atom’s center, called the nucleus. It tells us what the element is!
• Mass Number ($A$): This is the total number of protons and neutrons in the nucleus. You can find it using this formula: $A = Z + N$ Here, $N$ stands for the number of neutrons.

Step 2: Find the Atomic Number

Look for the atomic number of the element you’re interested in. You can find this information on the periodic table. For example, carbon has an atomic number of 6.

Step 3: Find the Number of Neutrons

Now, you may need to look up or calculate how many neutrons there are. You can usually get this from the mass number of a specific version of the element, known as an isotope. Sometimes, the mass number is on the periodic table or in other resources.

Step 4: Do the Math

Now, use the formula with the numbers you have:

• If carbon has 6 protons and let’s say it has 6 neutrons, you would do: $A = Z + N = 6 + 6 = 12$

Conclusion

And there you go! You’ve found the mass number of the atom! Isn’t that cool? Keep practicing with different elements, and you’ll become a pro at this before you know it! Happy calculating!