Group similarities in the Periodic Table

Steps:

• Germanium (Ge, group 14, period 4) and selenium (Se, group 16, period 4) are adjacent in the same period.
• Elements in the same group share valence electrons, leading to similar properties down the group.
• Tin (Sn) is in group 14, period 5, directly below Ge.
• Thus, Ge and Sn exhibit similar chemical behaviors, such as forming +4 oxidation states and covalent compounds.

Why C is correct:

• Elements in the same group have analogous valence electron configurations, predicting similar reactivity per the periodic law.

Why the others are wrong:

• A: Ge typically forms Ge⁴⁺ or covalent bonds, not Ge²⁺; Se forms Se²⁻, but ion charges aren't directly predicted by group position alone.
• B: While true due to decreasing metallic character across a period, it's based on horizontal trends, not the primary vertical group similarity emphasized here.
• D: Ge is similar to Sn (same group), not tellurium (Te, group 16); Se is similar to Te, not Sn.

Final answer: C