To achieve a noble gas configuration, group 15 elements (also known as the nitrogen group) need to gain 3 electrons. Group 15 elements have 5 valence electrons, and noble gases have a full outer energy level with 8 valence electrons. Therefore, group 15 elements, such as nitrogen (N), phosphorus (P), arsenic (As), etc., would need to gain 3 electrons to achieve a noble gas configuration.
