Final answer:
The ionization energy of the one-electron ion Be3 is 899 kJ/mol.
Step-by-step explanation:
The ionization energy (IE) of the one-electron ion Be3 can be calculated by using the equation:
A(g) → A+(g) + e-
Since Be3 is a one-electron ion, we can consider it as Beryllium (Be) losing one electron. The first ionization energy (IE₁) can be determined by referring to Figure 3.34, which shows the first ionization energies of selected elements. For Beryllium, the ionization energy value is 899 kJ/mol. So, the ionization energy of the one-electron ion Be3 is 899 kJ/mol.