The section presents a question related to atomic physics, specifically regarding the energy required to remove an electron from an atom. The key topics include:

- **Ionization Energy**: The energy needed to remove an electron from an atom.
- **Binding Energy**: The energy that holds the electron within the atom.
- **Free Energy**: A thermodynamic quantity that measures the usable energy.
- **Chemical Energy**: The energy stored in the bonds of chemical compounds.

The question provides four answer options, with the correct answer being "A. Năng lượng ion hóa" (Ionization Energy).