(b) Would you expect it to require more or less energy to remove a 3s electron from the chlorine atom, as compared with a 2p electron?

Verified step by step guidance

1. Understand the concept of ionization energy, which is the energy required to remove an electron from an atom in the gaseous state.
2. Recall the electron configuration of chlorine: Cl has the configuration \(1s^2 2s^2 2p^6 3s^2 3p^5\). This indicates that chlorine has electrons in the 3s and 2p orbitals.
3. Consider the effective nuclear charge experienced by electrons in different orbitals. Electrons in the 2p orbital are closer to the nucleus and experience a higher effective nuclear charge compared to electrons in the 3s orbital.
4. Recognize that electrons closer to the nucleus (such as those in the 2p orbital) are held more tightly due to the stronger attraction from the nucleus, requiring more energy to remove them.
5. Conclude that it would require less energy to remove a 3s electron compared to a 2p electron from a chlorine atom, due to the lower effective nuclear charge experienced by the 3s electron.

Key Concepts

Electron Shells and Energy Levels

Electrons in an atom are arranged in shells or energy levels, with each shell corresponding to a specific distance from the nucleus. The 2p electrons are in a lower energy level (n=2) compared to the 3s electrons (n=3). Generally, electrons in higher energy levels are further from the nucleus and experience less effective nuclear charge, making them easier to remove.

Effective Nuclear Charge (Z_eff)

Effective nuclear charge refers to the net positive charge experienced by an electron in a multi-electron atom. It accounts for the shielding effect of inner electrons that reduce the full nuclear charge. In chlorine, the 3s electron experiences a lower Z_eff compared to the 2p electron due to increased shielding, which influences the energy required for electron removal.

Ionization Energy

Ionization energy is the energy required to remove an electron from an atom in its gaseous state. It generally increases with higher nuclear charge and decreases with increased electron shielding. Since the 3s electron in chlorine is further from the nucleus and experiences more shielding than the 2p electron, it requires less energy to remove, leading to a lower ionization energy for the 3s electron.