Read the Assertion and Reason below and choose the correct option. — Atomic Structure Chemistry Question

💡 Solution & Explanation

Statement II is correct and provides the required formulas for calculating nodes. The total nodes for any orbital is given by $(n - 1)$. For oxygen ($1s^2 2s^2 2p_x^2 2p_y^1 2p_z^1$), the occupied orbitals are 1s, 2s, $2p_x$, $2p_y$, and $2p_z$. Their respective total nodes are: 1s ($1-1=0$), 2s ($2-1=1$), $2p_x$ ($2-1=1$), $2p_y$ ($2-1=1$), and $2p_z$ ($2-1=1$). The sum of all nodes is $0 + 1 + 1 + 1 + 1 = 4$. Statement I is correct, and Statement II explains how to derive it. Therefore, correct answer is A.