Example 1 · difficulty 2/5
In a proposed Dobereiner triad, the atomic masses of the first and third elements are 6.9 u and 39.1 u. What atomic mass is expected approximately for the middle element?
- A. 20.0 u
- B. 23.0 u
- C. 32.0 u
- D. 46.0 u
2019 source guide · Chemistry
NEET 2019 Chemistry Periodic Properties Questions
Connect the official 2019 paper with current Chemistry practice without labelling original previews as PYQs.
150 original questions · explicit provenance labels
ChemistryPlate 65
NeetVellum atlas · fig. chemistry
65
What to master
periodic trends, effective nuclear charge and anomalous behaviour.
Original practice preview
These are current-syllabus NeetVellum questions, shown separately from historical-paper provenance.
Example 2 · difficulty 1/5
Which set is a recognised example of a Dobereiner triad?
- A. Li, Mg, K
- B. F, Cl, I
- C. Ca, Sr, Ba
- D. C, Si, Sn
Example 3 · difficulty 1/5
Why could Dobereiner's triads not serve as a general classification of all known elements?
- A. They used atomic numbers before atomic numbers were known
- B. They included only gaseous elements
- C. They denied all similarities among elements
- D. Only a limited number of elements could be grouped into satisfactory triads
The evidence-first practice loop
- 1. Verify provenanceOfficial paper and final key before accepting a PYQ label.
- 2. Attempt closed-bookExpose the concept or execution gap before rereading.
- 3. Repair and returnClassify the miss and re-practice after a delay.
Canonical chapter practice
Frequently asked questions
Are these official NEET 2019 Chemistry Periodic Properties PYQs?
No. The previews are original NeetVellum practice questions. A historical item receives a PYQ label only after its official paper and authoritative final answer key are attached. Use the official archive for the source paper.
How should I use the NEET 2019 paper?
Solve the official paper under its original timing, verify against the final key, classify every miss, and then use the linked current-syllabus practice bank to repair the exposed concept.