Which of the following sequences correctly represents the increasing order of forces of attraction between particles? MCQ with Answer and Explanation

Explanation:
Cathode (negative electrode): 2H₂O + 2e⁻ → H₂ + 2OH⁻ (or 2H⁺ + 2e⁻ → H₂). Hydrogen gas is collected at the cathode. At the anode, oxygen is produced: 2H₂O → O₂ + 4H⁺ + 4e⁻. The volume of H₂ is double that of O₂.

Explanation:
Brittleness is a property typical of non-metals and metalloids; metals are ductile and malleable, not brittle. Ductility: drawn into wires (gold most ductile). Malleability: beaten into sheets (gold most malleable). Metals also have luster, high thermal and electrical conductivity, and sonorous nature. Brittle substances break easily under stress without significant deformation (e.g., glass, sulfur). Some metals like cast iron are brittle but generally pure metals are not.

Explanation:
The modern periodic law states that properties of elements are periodic functions of their atomic numbers (number of protons). This was established by Henry Moseley. Mendeleev's original table used atomic mass, but the modern table resolves anomalies by ordering by atomic number.