7.1. The Nucleus

• What is the nucleus of an atom?

  Central core with protons and neutrons
• The nucleus is the central core of an atom that contains protons and neutrons.
• The nucleus occupies a tiny fraction of the atom's total volume.

  True
• What is the mass of a proton in kilograms?

  1.6726 \times 10^{-27}</latex>
• The number of protons in the nucleus defines the atomic number.


  True
• What is the atomic number (Z) of an atom?

  Number of protons
• The notation A_ZX represents the atomic number, mass number, and chemical symbol of an element.


  True
• What is the atomic number (Z) of an atom?

  Number of protons
• Isotopes are atoms of the same element with the same atomic number but different mass numbers.
• All carbon isotopes have the same atomic number.


  True
• What remains the same for isotopes of the same element?

  Atomic Number (Z)
• What are the mass numbers of the three naturally occurring isotopes of carbon: Carbon-12, Carbon-13, and Carbon-14?

  12, 13, 14
• What are the magic numbers of protons and neutrons that correspond to particularly stable nuclei?

  2, 8, 20, 28, 50, 82, 126
• Arrange the following nucleus types based on their stability and N/Z ratio:

  1️⃣ Light Nuclei (N/Z ≈ 1)

  2️⃣ Heavy Nuclei (N/Z > 1)

  3️⃣ Unstable Nuclei (Far from Band)
• What is the charge of a proton?

  +1
• What is the nucleus of an atom composed of?

  Protons and neutrons
• The mass number of an atom is the total number of protons and neutrons in the nucleus.


  True
• The strong nuclear force is stronger than the electrostatic repulsive force at short distances within the nucleus.

  True
• As the number of protons in a nucleus increases, the electrostatic repulsive force becomes more significant.


  True
• What is the approximate proton-to-neutron ratio for stable nuclei?

  Close to 1
• Over what distance does the strong nuclear force act?

  Short distance
• The band of stability plots the number of neutrons against the number of protons.
• Steps of radioactive decay processes:

  1️⃣ Alpha Decay

  2️⃣ Beta Decay

  3️⃣ Gamma Decay
• The model that describes energy levels within the nucleus is called the nuclear shell model.
• Neutrons have a positive charge.

  False
• What is the charge of a proton?

  Positive (+1)
• What is the charge of a neutron?

  Neutral (0)
• The mass number (A) is the total number of protons and neutrons in the nucleus.
• The atomic number (Z) defines the element's identity because each element has a unique number of protons.
• The atomic number (Z) is the number of protons in the nucleus.
• The atomic number (Z) defines the element's identity.


  True
• What distinguishes isotopes of the same element?

  Different number of neutrons
• What is the defining characteristic of isotopes in terms of their atomic number (Z) and mass number (A)?

  Same Z, different A
• The mass number varies for different isotopes of the same element.


  True
• The different mass numbers of carbon isotopes reflect the varying number of neutrons
• Nuclei with a proton-to-neutron ratio close to 1 tend to be more stable
• What equation relates nuclear binding energy and mass defect?

  $E =$$mc^{2}$
• Protons and neutrons are collectively called nucleons.


  True
• Neutrons are electrically neutral
• Isotopes of the same element have the same atomic number but different mass