Exam-style question
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If an atom has 15 protons and 18 neutrons, what is its atomic number?.
- A.15
- B.18
- C.33
- D.3
Model answer
What a good answer should say
- 15
Explanation
Why this works
The atomic number of an atom is defined as the number of protons it contains. Therefore, this atom has an atomic number of 15.
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