Which atom can have more than eight valence electrons when it is forming covalent bonds? — Chemical Bonding Chemistry Question

💡 Solution & Explanation

Step 1: Elements in the third period and beyond have vacant d-orbitals in their valence shell, allowing them to expand their octet to accommodate more than 8 electrons. Step 2: Hydrogen (1st period), Nitrogen, and Fluorine (2nd period) have no d-orbitals and are strictly limited to a maximum of 2 (for H) or 8 valence electrons (for N, F). Step 3: Chlorine belongs to the 3rd period and possesses vacant 3d orbitals, allowing it to easily expand its octet (e.g., holding 10 electrons in ClF3). This corresponds to option (d).