Answer:
B: 18
Step-by-step explanation:
On the Periodic Table of Elements, the elements are labeled with many numbers. But to find how many protons are in an atom, the largest number in the center is the number of protons in that element.
For example, Argon is in the eighteenth group, third period. It is labeled with a big 18, which means that there are 18 protons in the nucleus of an Argon atom.