Helium and beryllium have similar outer electronic configuration of the type ns2. — Periodic Table and Periodicity Chemistry Question

💡 Solution & Explanation

Step 1: The 2p subshell is located in the second period (n=2) of the periodic table. Step 2: An element containing exactly three 2p electrons will have the electronic configuration 1s2 2s2 2p3. Step 3: Summing the electrons (2 + 2 + 3 = 7) gives the atomic number 7, which corresponds to Nitrogen (N).