UPSC Combined Geo-Scientist, Mains · 2021 · Mains Paper III
Q4(a). X-ray fluorescence: theoretical basis; bulk against surface
Question
Briefly discuss about the theoretical basis of X-Ray Fluorescence (XRF) method. “XRF gives information about the bulk sample, not just the surface atoms as in Auger work.” Explain why.
Model answer
The free solution for 2021 answers questions 1, 2, 5, 6, 7 and 10, the ones picked in its time plan. Question 4 is answered in full in the Geo-Scientist Chemistry Paper III, 2021 to 2025 book, with every part of every paper.
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UPSC Combined Geo-Scientist (Main) Chemistry Paper III: Model Answers 2021 to 2025
- All ten questions of each paper, with the question printed above its answer
- Instruments drawn as labelled diagrams, numericals worked with units
- Topic-wise weightage and a topic-wise index
CoversX-ray fluorescenceXRFAuger electroncharacteristic X-raysbulk analysis
All parts of Question 4
- 4(a) X-ray fluorescence: theoretical basis; bulk against surface15 marks
- 4(b) Components of a UV–visible spectrophotometer and their functions10 marks
- 4(c) Scanning and isothermal thermogravimetry; the thermobalance5 marks