Key Takeaways
Lesson Description
Key Takeaways
• Matter is composed of atoms containing protons, neutrons, and electrons.
• Atomic number = number of protons; Mass number = protons + neutrons.
• Isotopes have the same number of protons but different numbers of neutrons.
• Average atomic mass is calculated using isotopic abundance.
• Electron configuration follows the Aufbau Principle, Hund's Rule, and Pauli Exclusion Principle.
• Valence electrons determine chemical properties and bonding behavior.
• Coulomb's Law explains attraction between charged particles.
• Photoelectron Spectroscopy (PES) identifies electron energy levels.
Must Know Equations
Coulomb's Law (conceptual):
F ∝ (q₁q₂)/r²
Must Know Vocabulary
Atom
Atomic Number
Mass Number
Isotope
Ion
Electron Configuration
Valence Electron
Orbital
PES
Coulomb's Law
AP Exam Focus
• Interpret electron configurations.
• Compare atomic radius, ionization energy, and electronegativity trends.
• Analyze Photoelectron Spectroscopy graphs.