Final answer:
A neutral magnesium atom, with an atomic number of 12, has 12 protons and 12 electrons, ensuring its neutrality due to the equal balance of positive and negative charges.
Step-by-step explanation:
The atomic number of an element indicates the number of protons in the nucleus of an atom of that element. For a neutral atom, the number of electrons is equal to the number of protons to balance the positive and negative charges. Therefore, for magnesium, which has an atomic number of 12, the correct statement about a neutral magnesium atom is that a) It has 12 protons and 12 electrons.
A neutral magnesium atom has 12 protons and 12 electrons. Protons are positively charged particles found in the nucleus of an atom, while electrons are negatively charged particles that orbit the nucleus. In a neutral atom, the number of protons is equal to the number of electrons.