(You can try these, these words can represent "system".) Method or methods, organization, routine, strategy, or operation.
Sodium
Atomic mass: 22.989769 u
Atomic number: 11
Protons: 11
Neutrons: 12
Electrons: 11
Protons and electrons are the same number, and the atomic number is the amount of electrons and protons it will have.
After the author's name you write the title in capital letters and I think it also might be italicized.
Answer:
I would go with choice c.
Explanation: