Aluminum matches all oxide and bonding properties in Period 3

Steps:

• Period 3 candidates: Mg (group 2), Al (group 13), Si (group 14), P (group 15).
• Giant oxide structure: MgO and Al2O3 (ionic lattices); SiO2 (covalent lattice); excludes P (P4O10 molecular).
• Covalent Cl bonds: AlCl3, SiCl4, PCl5 covalent; excludes Mg (MgCl2 ionic).
• Oxide neutralizes HCl: MgO and Al2O3 react (basic/amphoteric); excludes Si (SiO2 acidic, inert to HCl) and P (P4O10 forms acid).

Why B is correct:

• Al2O3 giant ionic structure, AlCl3 covalent (dimer), Al2O3 + 6HCl → 2AlCl3 + 3H2O (acid-base reaction).

Why the others are wrong:

• A. Mg: MgCl2 ionic, not covalent.
• C. Si: SiO2 does not react with HCl(aq).
• D. P: P4O10 molecular structure, not giant.

Final answer: B