Atoms: Class 12 Physics (UP Board) important questions and practice
Atoms is chapter 12 of 14 in UP Board Class 12 Physics. Below are the topics the paper draws from, the question types that come up again and again, and a free practice test on this chapter alone.
Topics in this chapter
- Alpha-particle scattering and Rutherford's nuclear model
- Distance of closest approach and impact parameter
- Bohr model of the hydrogen atom: postulates, radius, velocity and energy of orbits
- Energy levels and the line spectra of hydrogen (Lyman, Balmer, Paschen series)
- de Broglie's explanation of Bohr's second postulate
- Limitations of the Bohr model
What examiners usually ask
- State Bohr's postulates and derive the expression for the radius of the nth orbit and the energy of the electron
- The ground state energy of hydrogen is -13.6 eV; find the energy and wavelength of the photon emitted in the transition n = 3 to n = 2
- Explain how de Broglie's hypothesis justifies Bohr's quantisation condition
Exam tip
Derive r_n proportional to n^2 and E_n = -13.6/n^2 eV and draw the energy level diagram with the series marked; numericals on wavelength use 1/lambda = R(1/n1^2 - 1/n2^2) and the hc = 1240 eV nm shortcut saves time.
Atoms on other boards and exams
Frequently asked questions
What are the important questions from Atoms for UP Board Class 12?
The question types listed above repeat most often in UP Board Class 12 Physics papers for this chapter. Practise them with the chapter test and then attempt them inside a full previous-year paper under time.
Is Atoms in the UP Board Class 12 Physics syllabus?
Yes. Atoms is part of the current UP Board Class 12 Physics syllabus, as listed on this site from the prescribed textbook.
Can I practise Atoms MCQs in Hindi?
Yes. The chapter test and explanations are available in Hindi and English, with an AI doubt solver for any question.