Germanium has a lower ionization energy than silicon but is found to have a higher ionization energy than gallium. Explain.

• A. Germanium has a lower ionization energy than silicon because its shielding effect is stronger. On the other hand, germanium has a higher ionization energy than gallium because its effective nuclear charge is higher.
• B. Germanium has a lower ionization energy than silicon because its shielding effect is stronger. On the other hand, germanium has a higher ionization energy than gallium because its effective nuclear charge is lower.
• C. Germanium has a lower ionization energy than silicon because its shielding effect is weaker. On the other hand, germanium has a higher ionization energy than gallium because its effective nuclear charge is lower.
• D. Germanium has a lower ionization energy than silicon because its shielding effect is weaker. On the other hand, germanium has a higher ionization energy than gallium because its effective nuclear charge is higher.

Answer: (A)