JEE Main · 2026 · 05 Apr 2026 · Shift 2 · Atomic Structure

By the $(n+\ell )$ rule, when two orbitals share the same $(n+\ell )$ value the one with the smaller $n$ is lower in energy, so statement (A) is correct. For a given subshell the orbital energy becomes more negative, i.e. decreases, as atomic number rises because of the greater nuclear charge, so statement (B) is incorrect. Orbital size increases with the principal quantum number, hence $2p_x$ is smaller than $3p_x$ and statement (C) is correct. The number of radial nodes is $n-\ell -1$, which for a $5d$ orbital is $5-2-1=2$, so a $5d$ orbital does possess two radial nodes and statement (D) is incorrect. The true statements are A and C only.