Which of the following electronic configurations correctly represents an element in period 3 of the periodic table?
Answer Details
Period 3 of the periodic table includes the elements sodium (Na), magnesium (Mg), aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), and chlorine (Cl). The correct electronic configuration for an element in period 3 should have 3 energy levels and electrons distributed among those energy levels according to the Aufbau principle. Looking at the options given: - represents an element in period 2 as it has only 2 energy levels. - represents the noble gas configuration of the element neon (Ne) in period 2. - represents an element in period 3 with 3 energy levels, where the outermost energy level has 6 electrons (3s2 3p4). This configuration is consistent with the element sulfur (S). - represents an element in period 4 as it has 4 energy levels. Therefore, the correct option representing an element in period 3 is with the electronic configuration 1s2 2s2 2p6 3s2 3p4.