How many protons are present in an atom of aluminum (Al)?

• A. 27
• B. 14
• C. 12
• D. 13

Answer: (D)

Verified step by step guidance

1. Recall that the number of protons in an atom is given by its atomic number, which is unique for each element.
2. Identify the element in question, which is aluminum (Al).
3. Look up the atomic number of aluminum on the periodic table; this number represents the number of protons.
4. Note that the atomic number of aluminum is 13, meaning every aluminum atom has 13 protons.
5. Understand that the mass number (such as 27 for aluminum) represents the total number of protons and neutrons, not just protons.