Second E.A. for halogens is almost zero. — Periodic Table and Periodicity Chemistry Question

💡 Solution & Explanation

Step 1: An element with 9 protons has an atomic number of Z=9, which is Fluorine (F). Step 2: Determine its ground state electronic configuration: 1s2 2s2 2p5 (or 2, 7 in shells). Step 3: Fluorine has 7 valence electrons and needs 1 electron to complete its octet and achieve stable noble gas configuration. Its combining capacity, or valency, is therefore 1.