MDCAT Chemistry — Atomic Structure
Atomic Structure is a core Chemistry topic in the PMDC MDCAT syllabus, covering 9 subtopics. Below are the subtopics to revise, how often the topic appears in past papers, and real past-paper MCQs to try.
Subtopics (9)
- Discovery of Electron (Cathode Rays)
- Discovery of Proton
- Electronic Configuration
- Ionization Energy of Hydrogen (Bohr Model)
- Mass Spectrometry
- Planck's Quantum Theory
- Quantum Numbers
- Shapes of Orbitals
- Spectrum of Hydrogen
How Atomic Structure is tested
Across the 16 MDCAT past papers on ParhaiKrlo, Atomic Structure accounts for 50 questions. It appears in all 16, about 3.1 questions a paper. The heaviest was MDCAT 2024, with 5 questions, and the most recent is MDCAT 2025, with 4.
| Paper | Questions |
|---|---|
| MDCAT 2025 | 4 |
| MDCAT 2024 | 5 |
| MDCAT 2023 | 5 |
| MDCAT 2022 | 1 |
| MDCAT 2019 | 2 |
| MDCAT 2018 | 1 |
| MDCAT 2017 | 5 |
| MDCAT 2016 | 2 |
| MDCAT 2015 | 4 |
| MDCAT 2014 | 2 |
| MDCAT 2013 | 2 |
| MDCAT 2012 | 2 |
| MDCAT 2011 | 3 |
| MDCAT 2010 | 5 |
| MDCAT 2009 | 5 |
| MDCAT 2008 | 2 |
Atomic Structure MCQs from the MDCAT past papers
Try each one before opening the answer. Each comes with a short explanation.
- Q1 · MDCAT 2025 · Atomic Structure
Which set of quantum numbers is not allowed for an electron?
- A.n=2, l=1, m=0, s=+1/2
- B.n=3, l=0, m=0, s=-1/2
- C.n=2, l=2, m=1, s=+1/2
- D.n=1, l=0, m=0, s=+1/2
Show answer
Answer: C. n=2, l=2, m=1, s=+1/2 — n=2, l=2, m=1, s=+1/2 is not allowed because l cannot equal or exceed n.
- Q2 · MDCAT 2024 · Atomic Structure
The type and relative amount of each isotope in an element can be found by:
- A.R spectroscopy
- B.U. V spectroscopy
- C.Mass Spectrometry
- D.N.M.R
Show answer
Answer: C. Mass Spectrometry — Mass spectrometry identifies isotopes and measures their relative abundance.
- Q3 · MDCAT 2023 · Atomic Structure
When 6d orbital is filled, the entering electron goes into:
- A.7f
- B.7d
- C.7p
- D.7s
Show answer
Answer: C. 7p — After the 6d orbital fills, the next electron enters the 7p orbital, following the standard Aufbau filling order.