Within an atom, electrons:

• A. have a positive charge
• B. are heavier than protons
• C. are found only inside the nucleus
• D. occupy specific energy levels around the nucleus

Answer: (D)

Verified step by step guidance

1. Understand the nature of electrons within an atom: Electrons are subatomic particles with a negative charge, much lighter than protons and neutrons.
2. Recall the structure of an atom: The nucleus contains protons and neutrons, while electrons are found outside the nucleus.
3. Recognize that electrons do not randomly float around the nucleus but occupy specific regions called energy levels or shells.
4. These energy levels represent quantized states where electrons can exist without radiating energy, according to quantum theory.
5. Therefore, the correct description is that electrons occupy specific energy levels around the nucleus, not inside it or with positive charge.