Bohr Model of the Atom Steps:

• Recall the simple atomic model where particles orbit a central core.
• Identify the central core as the nucleus, containing protons and neutrons.
• Recognize electrons as negatively charged particles orbiting the nucleus.
• Match the phrase "X is around Y" to electrons surrounding the nucleus.

Why A is correct:

• In the Bohr model, electrons orbit the nucleus, forming electron shells around the positively charged core.

Why the others are wrong:

• B: Neutrons reside in the nucleus, not around electrons.
• C: The nucleus contains protons but is not around them.
• D: Protons and neutrons both form the nucleus, not one around the other.

Final answer: A