Final answer:
Aluminum requires the greatest amount of energy to remove one electron from its outer energy level.
Step-by-step explanation:
The element that requires the greatest amount of energy to remove one electron from its outer energy level is Aluminum. Aluminium has three valence electrons in its outer energy level, which requires a significant amount of energy to remove. Magnesium, Carbon, and Nitrogen have 2, 4, and 5 valence electrons respectively, making them require less energy to remove an electron compared to Aluminum.
Learn more about Energy required to remove electrons from outer energy level