Answer
6
Work Step by Step
The atomic number of an atom is equal to the number of protons. The diagram identifies that there are 6 protons, so it follows that the atomic number is 6.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.