The number of f electrons in the ground state electronic configuration of Np (Z = 93) is ________. ( — d and f Block Elements Chemistry Question

💡 Solution & Explanation

**Step 1: Determine the electron configuration of Np (Z = 93)** For Neptunium with 93 electrons, use the Aufbau principle following the order of orbital filling: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f⁴ 6s² 6p⁶ 6d¹ 7s² **Step 2: Identify the f-orbital electrons** The f orbitals that contain electrons are: - 4f¹⁴ (completely filled) - 5f⁴ (partially filled) **Step 3: Count total f electrons** Total f electrons = electrons in 4f + electrons in 5f Total f electrons = 14 + 4 = 18 **Step 4: Verify the total electron count** Sum of all electrons in the configuration: 2 + 2 + 6 + 2 + 6 + 10 + 2 + 6 + 10 + 14 + 2 + 6 + 10 + 4 + 2 + 6 + 1 + 2 = 93 ✓ Therefore, the answer is **18.00**.