Chemistry

Question Analysis
This question involves bonding type and physical properties of compounds. The main focus is on identifying a substance that has both a high melting point and good electrical conductivity when dissolved in water, which are characteristic properties of ionic compounds.

Key Concept Explanation
Ionic compounds typically have high melting points due to strong electrostatic attractions between ions. They can conduct electricity when dissolved in water because the ions are free to move.

Step-by-step Solution
1. Identify the type of compound: $$\text{H}_2\text{O}$$, $$\text{CH}_4$$, and $$\text{CO}_2$$ are covalent compounds, while $$\text{NaCl}$$ is an ionic compound.
2. Determi...