AP Physics 2 Questions: Electron Configuration and Pauli's Exclusion Principle

📚 Quick Study Guide

• ⚛️ Electron Configuration: Describes the arrangement of electrons within an atom. It follows specific rules to fill orbitals.
• 🧱 Aufbau Principle: Electrons first fill the lowest energy levels available. The order is generally: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p.
• 🖐️ Hund's Rule: Within a subshell, electrons individually occupy each orbital before any orbital is doubly occupied, and all electrons in singly occupied orbitals have the same spin.
• 📐 Pauli Exclusion Principle: No two electrons in the same atom can have the same set of four quantum numbers ($n, l, m_l, m_s$). This means each orbital can hold a maximum of two electrons, which must have opposite spins.
• 💡 Quantum Numbers:
  • Principal Quantum Number ($n$): Energy level (1, 2, 3, ...).
  • Azimuthal Quantum Number ($l$): Shape of the orbital (0 = s, 1 = p, 2 = d, 3 = f).
  • Magnetic Quantum Number ($m_l$): Orientation of the orbital (-$l$ to +$l$, including 0).
  • Spin Quantum Number ($m_s$): Spin of the electron (+1/2 or -1/2).

🧪 Practice Quiz

1. What is the maximum number of electrons that can occupy a *p* subshell?
   1. 2
   2. 4
   3. 6
   4. 8
2. Which of the following electron configurations violates the Pauli Exclusion Principle?
   1. 1s² 2s² 2p⁶
   2. 1s² 2s² 2p⁴
   3. 1s² 2s² 2p⁶ 3s² 3p⁶
   4. 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶
3. According to the Aufbau principle, which orbital is filled immediately after the 4*s* orbital?
   1. 4*p*
   2. 4*d*
   3. 5*s*
   4. 3*d*
4. Which quantum number describes the shape of an atomic orbital?
   1. Principal quantum number (*n*)
   2. Azimuthal quantum number (*l*)
   3. Magnetic quantum number (*m_l*)
   4. Spin quantum number (*m_s*)
5. What is the maximum number of electrons that can have the quantum numbers *n* = 3 and *l* = 2?
   1. 2
   2. 6
   3. 10
   4. 14
6. Which of the following is the correct electron configuration for potassium (K), which has 19 electrons?
   1. 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
   2. 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
   3. 1s² 2s² 2p⁶ 3s² 3p⁵ 4s²
   4. 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹
7. Which rule states that electrons fill orbitals individually before pairing up in the same orbital?
   1. Aufbau Principle
   2. Pauli Exclusion Principle
   3. Hund's Rule
   4. Heisenberg Uncertainty Principle