Consider the following elements with their electronegativity value. Elements A B C D Electronegativi — Periodic Table and Periodicity Chemistry Question

💡 Solution & Explanation

Step 1: Determine the electronic configurations of beryllium (Be: 1s2 2s2), magnesium (Mg: 1s2 2s2 2p6 3s2), and calcium (Ca: 1s2 2s2 2p6 3s2 3p6 4s2). Step 2: Compare their outermost energy levels. All three elements have two s-electrons in their outermost shells, are classified as alkaline earth metals, and belong to group 2 of the periodic table. Step 3: Beryllium has only 4 electrons total, and its outer energy level (n=2) contains no p-orbitals or p-electrons. Therefore, containing a pair of p-electrons in the outermost energy level is not a shared characteristic.