| List-I (Type of Crystalline Solid) | List-II (Example) |
| (A) Ionic | (III) Sodium Chloride, NaCl |
| (B) Covalent | (IV) Diamond, C |
| (C) Molecular | (I) Methane, CH4 |
| (D) Metallic | (II) Copper, Cu |
Crystalline solids are classified based on their bonding types:
• Ionic solids: Characterized by electrostatic forces (e.g., NaCl).
• Covalent solids: Feature covalent network bonds (e.g., Diamond, C).
• Molecular solids: Held together by weak forces (e.g., Methane, CH4).
• Metallic solids: Possess delocalized electrons (e.g., Copper, Cu).
The correct answer is: (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
Which of the following statements are true?
A. Unlike Ga that has a very high melting point, Cs has a very low melting point.
B. On Pauling scale, the electronegativity values of N and C are not the same.
C. $Ar, K^{+}, Cl^{–}, Ca^{2+} and S^{2–}$ are all isoelectronic species.
D. The correct order of the first ionization enthalpies of Na, Mg, Al, and Si is Si $>$ Al $>$ Mg $>$ Na.
E. The atomic radius of Cs is greater than that of Li and Rb.
Choose the correct answer from the options given below: