It's easier to remove an electron from a sodium atom than a magnesium atom because of their electron configurations and the resulting stability of the ions formed. Here's why:

* Electron Configuration:

* Sodium (Na): 1s² 2s² 2p⁶ 3s¹

* Magnesium (Mg): 1s² 2s² 2p⁶ 3s²

* Sodium has one electron in its outermost shell (3s), while magnesium has two.

* Ionization Energy: The energy required to remove an electron from an atom is called ionization energy. The lower the ionization energy, the easier it is to remove an electron.

* Stability of Ions:

* Sodium Ion (Na⁺): 1s² 2s² 2p⁶ (Stable noble gas configuration like Neon)

* Magnesium Ion (Mg²⁺): 1s² 2s² 2p⁶ (Stable noble gas configuration like Neon)

Here's the breakdown:

1. Sodium (Na) loses one electron to become Na⁺. This results in a filled outer shell, making the ion very stable. It achieves the stable electron configuration of Neon.

2. Magnesium (Mg) loses two electrons to become Mg²⁺. While also resulting in a filled outer shell, the second ionization energy for magnesium is much higher than the first. This is because removing the second electron disrupts the stable 3s² configuration, making it harder to remove.

In summary:

* Sodium has a lower first ionization energy than magnesium because it's easier to remove a single electron to achieve a stable noble gas configuration.

* Magnesium has a higher first ionization energy because it requires more energy to remove the first electron. While it becomes more stable after losing both electrons, the second ionization energy is significantly higher due to the disruption of the initially stable configuration.