Which atom has a nucleus that contains 13 protons and 14 neutrons?

• A. Silicon-27
• B. Magnesium-27
• C. Aluminum-26
• D. Aluminum-27

Answer: (D)

Verified step by step guidance

1. Identify the number of protons in the nucleus, which defines the element's atomic number. Here, the nucleus contains 13 protons, so the atomic number is 13.
2. Recall that the atomic number corresponds to a specific element on the periodic table. The element with atomic number 13 is Aluminum (Al).
3. Determine the number of neutrons in the nucleus, which is given as 14 neutrons.
4. Calculate the mass number by adding the number of protons and neutrons: \(\text{mass number} = 13 + 14\).
5. Match the mass number with the isotope notation: Aluminum with a mass number of 27 is written as Aluminum-27, confirming the correct answer.