Arrange the following atoms in order of decreasing energy needed to remove the most tightly held electron (the electron closest to the nucleus).

Na, Mg, Al, P

Question

Arrange the following atoms in order of decreasing energy needed to remove the most tightly held electron (the electron closest to the nucleus).

Na, Mg, Al, P

Quizplus · Accepted Answer

The energy needed to remove the most tightly held electron generally increases across a period (from left to right in the periodic table) due to increasing nuclear charge and decreases down a group due to increasing atomic radius and electron shielding. Given the elements Na (sodium), Mg (magnesium), Al (aluminum), and P (phosphorus), they are arranged in the periodic table from left to right as Na, Mg, Al, P. Therefore, the order of decreasing energy needed to remove the most tightly held electron is P > Al > Mg > Na, as phosphorus is the furthest to the right and sodium is the furthest to the left.

Arrange the Following Atoms in Order of Decreasing Energy Needed