Скачать или смотреть 15-First Ionization Energy: Phosphorus vs Sulfur | AP Chemistry | IB Chemistry |General Chemistry

In this video, we solve a multiple-choice question comparing the first ionization energies of phosphorus (P) and sulfur (S). Although ionization energy generally increases across a period, this question highlights an important exception caused by electron pairing and sublevel stability.

We analyze:

Electron configurations of phosphorus and sulfur

The stability of half-filled p sublevels

The effect of electron–electron repulsion on ionization energy

How to eliminate incorrect answer choices using periodic trends

This type of question frequently appears in AP Chemistry, IB Chemistry (SL & HL), and other international exams.

Perfect for students who want to master ionization energy trends and exceptions with clear exam-style reasoning.

Keywords / Tags:

ionization energy

first ionization energy

phosphorus vs sulfur

ionization energy exceptions

electron configuration

half-filled sublevel

paired electrons

periodic trends

AP Chemistry

IB Chemistry

IB Chemistry SL

IB Chemistry HL

multiple choice chemistry questions

exam-style chemistry questions

p-block elements

periodic table trends

chemistry concept traps