H2 Chemistry Notes: CORE IDEA 1, Topic 1 - Atomic Structure
Download printable cheat-sheet (CC-BY 4.0)10 Feb 2025, 00:00 Z
Join our Telegram study groupQ: What does H2 Chemistry Notes: CORE IDEA 1, Topic 1 - Atomic Structure cover? A: Review quantum numbers, electron configurations, ionisation trends, and spectroscopy evidence for the Core Idea 1 Atomic Structure topic in the 2026 H2 Chemistry syllabus.
Atomic structure underpins every other area of H2 Chemistry. You need to know how quantum numbers define electron positions, how orbitals fill, and how evidence from spectroscopy backs the quantum model. These notes focus on the ideas that repeatedly appear in structured and data-based questions.
1 Quantum Numbers at a Glance
| Symbol | Name | Typical values | What it tells you |
| \(n\) | Principal quantum number | \(1, 2, 3, ...\) | Shell index; larger n means electrons are, on average, further from the nucleus and higher in energy. |
| \(l\) | Azimuthal (angular momentum) quantum number | \(0\) to \(n - 1\) | Subshell shape: \(l = 0 (s), 1 (p), 2 (d)\). |
| \(m_l\) | Magnetic quantum number | \(-l\) to \(+l\) | Orientation of the orbital in space. |
| \(m_s\) | Spin quantum number |
