CSCA ChemistryChapter 3: Chemical Theories and LawsBeginner
Atomic Structure & Periodic Law Trends
原子结构模型与元素周期律递变规律 · Node 3.1
Nuclear structure (protons, neutrons, electrons), effective nuclear charge, atomic radius, and ionization energy trends.
Chapter Weight: 25% of official examination
Practice This NodeCore Mathematical Axiom
Formula Proof & TrapsCSCA Exam Trap Alert
Overlooking half-filled 2p^3 stability in Nitrogen (which gives it higher 1st ionization energy than Oxygen).