A neutral atom of calcium has how many protons and how many electrons?

• A. 20 protons and 20 electrons
• B. 12 protons and 12 electrons
• C. 22 protons and 22 electrons
• D. 18 protons and 18 electrons

Answer: (A)

Verified step by step guidance

1. Identify the atomic number of calcium from the periodic table. The atomic number represents the number of protons in the nucleus of an atom.
2. Recall that calcium has an atomic number of 20, which means it has 20 protons.
3. Understand that a neutral atom has no overall charge, so the number of electrons must equal the number of protons to balance the positive charge of the protons.
4. Since calcium is neutral, it must have 20 electrons to balance the 20 protons.
5. Conclude that a neutral calcium atom has 20 protons and 20 electrons.