The ionization energy generally increases as you move across a period from left to right in the periodic table. Additionally, within a given period, the ionization energy tends to increase as you move from the left side to the right side.
Let's compare the given electron configurations:
- (Ne) 3s2 3p3
- (Ne) 3s2 3p4
- (Ne) 3s2 3p5
- (Ne) 3s2
Among these configurations, the electron configuration with the highest ionization energy is (Ne) 3s2. This is because it has a completely filled valence shell (2 electrons in the 3s orbital), which makes it more stable compared to the other configurations.
The configuration (Ne) 3s2 3p3 has one unpaired electron in the 3p orbital, making it easier to remove compared to (Ne) 3s2. Similarly, (Ne) 3s2 3p4 and (Ne) 3s2 3p5 also have fewer electrons in the valence shell, making them easier to ionize compared to (Ne) 3s2.
Therefore, (Ne) 3s2 has the highest ionization energy among the given electron configurations.