JEE Main · 2023 · 08 Apr 2023 · Shift 1 · Atomic Structure

Each statement is weighed against how atomic spectra actually appear. Statement (A) is correct: line emission spectra arise from discrete electronic transitions and so reveal the electronic structure of the atom. Statement (B) is incorrect: atoms in the gas phase emit a line spectrum of discrete, separated wavelengths, not a continuous spread from red to violet, which is seen only from hot solids or dense sources. Statement (C) is correct: an absorption spectrum shows dark lines exactly where the emission spectrum shows bright ones, so it is like the photographic negative of the emission spectrum. Statement (D) is correct: helium was first identified from an unknown line in the Sun's spectrum. One statement is incorrect.