Correct Answer: B. Electrolytes contain mobile ions while conductors consist of mobile electrons
Explanation
Let's analyze each statement:
A. Electrolytes are compounds while conductors are elements.
• Electrolytes are compounds: This is generally true. Electrolytes are typically ionic compounds (like NaCl) or molecular compounds that ionize in solution (like HCl).
• Conductors are elements: This is false. While many excellent conductors are elements (e.g., copper, silver), many alloys (mixtures of elements, e.g., brass, steel) are also conductors. More importantly, electrolytes themselves are conductors, and they are compounds, not elements. If conductors refers to *metallic conductors*, then alloys disprove the statement.
• Conclusion for A: False.
B. Electrolytes contain mobile ions while conductors consist of mobile electrons.
• Electrolytes contain mobile ions: This is the defining characteristic of electrolytes. They conduct electricity through the movement of charged ions. This is true.
• Conductors consist of mobile electrons: When electrolytes are contrasted with conductors in this manner, conductors typically refers to *metallic conductors*. Metallic conductors conduct electricity through the movement of delocalized electrons. This is also true for metallic conductors. This statement highlights the fundamental difference in the mechanism of charge transport between electrolytic and metallic conduction.
• Conclusion for B: True, assuming conductors refers to metallic conductors (which is the standard distinction when electrolytes are mentioned separately).
C. Electrolytes can be solution while conductors are usually solids.
• Electrolytes can be solution: This is true. Many common electrolytes are aqueous solutions (e.g., salt water, acid solutions). They can also be molten (e.g., molten NaCl).
• Conductors are usually solids: If conductors refers to *metallic conductors*, then most are solids at room temperature (e.g., copper, aluminum). However, mercury is a liquid metallic conductor, and molten metals are liquid conductors. If conductors refers to *all types of conductors*, including electrolytes, then many conductors (like salt solutions, acids, molten salts) are liquids, making usually solids inaccurate. Given the ambiguity, and the existence of many liquid conductors, this statement is less universally true or fundamental than B.
• Conclusion for C: Potentially true with specific interpretations, but less robust than B. If conductors implies *all* conductors, it's likely false due to many liquid electrolytes.
D. Electrolytes and conductor can both be decomposed by an electric current.
• Electrolytes... can be decomposed by an electric current: This is true. The process of electrolysis involves using electric current to chemically decompose electrolytes (or the solvent) into simpler substances (e.g., decomposing water into H2 and O2, or molten NaCl into Na and Cl2).
• Conductor can both be decomposed by an electric current: If conductor refers to *metallic conductors*, then they are generally *not* chemically decomposed by an electric current. They facilitate the flow of electrons without undergoing chemical change themselves (unless subjected to extreme conditions causing melting or other physical damage, which isn't chemical decomposition by the current's action).
• Conclusion for D: False, as metallic conductors are not decomposed by an electric current.
Final assessment:
Statement A is false because conductors can be alloys.
Statement D is false because metallic conductors are not decomposed by an electric current.
Statement C is debatable depending on the interpretation of conductors. If conductors includes electrolytic solutions, then conductors are usually solids is false. If conductors refers only to metallic conductors, it's true, but less fundamental than B.
Statement B provides the most fundamental and accurate distinction between electrolytes (which conduct via mobile ions) and metallic conductors (which conduct via mobile electrons). This is a core concept in chemistry and physics.
Therefore, statement B is the most accurate and unequivocally true statement among the choices, assuming the common distinction between electrolytic and metallic conduction.
The final answer is B
