Identifying solids by crystal lattice structures

Steps:

• Recall sodium chloride (NaCl) forms an ionic lattice with alternating Na⁺ and Cl⁻ ions.
• Recognize potassium (K) as a metal with a metallic lattice of K⁺ ions in a sea of delocalized electrons.
• Identify krypton (Kr) as a noble gas solid with a face-centered cubic atomic lattice of Kr atoms.
• Match diagrams: X shows ionic arrangement (NaCl), Y metallic (K), Z atomic (Kr).

Why D is correct:

• Option D assigns X to NaCl (ionic lattice per ionic bonding definition), Y to potassium (metallic structure), and Z to krypton (monatomic atomic solid).

Why the others are wrong:

• A misassigns ionic X to krypton, which lacks ions.
• B confuses Y with nonexistent "sodium chloride" and Z with potassium.
• C incorrectly labels X as NaCl but mixes up Y and Z with invalid "krypton chloride."

Final answer: D