The atom has 20 protons. The atom has 20 neutrons. The sum of the number of protons and electrons is 20. The sum of the number of protons and neutrons is 20.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which statement best describes an atom with an atomic number of 20?
Possibilities:
- The atom has 20 protons.
- The atom has 20 neutrons.
- The sum of the number of protons and electrons is 20.
- The sum of the number of protons and neutrons is 20.

The atom has 20 protons.