Specific resistivity (electrical resistivity) of silver at standard conditions What is the approximate specific resistance (resistivity) of silver, expressed in Ω·m (ohm-metre), under normal room-temperature conditions?

Introduction / Context:Electrical resistivity ρ (also called specific resistance) characterizes how strongly a material opposes the flow of electric current. Among all common metals, silver is known for having the lowest resistivity, which is why it is often used as a benchmark and in high-performance conductors when cost permits.

Given Data / Assumptions:

• Material: silver (high-purity, bulk).
• Ambient temperature near room temperature (~20 °C to 25 °C).
• Standard units: Ω·m (ohm-metre).
• Typical handbook values are acceptable approximations.

Concept / Approach:

For metals, ρ increases with temperature and depends on purity and microstructure. However, standard values are widely quoted for comparison. Silver’s resistivity at ~20 °C lies around 1.59 × 10^-8 to 1.65 × 10^-8 Ω·m; tabulations often round to 1.60 × 10^-8 or 1.62 × 10^-8 Ω·m. Therefore, an option near 1.64 × 10^-8 Ω·m is the best choice among the given alternatives.

Step-by-Step Solution:

Verification / Alternative check:

Cross-check with copper for context: ρ_Cu ≈ 1.7 × 10^-8 Ω·m at room temperature, slightly higher than silver. This confirms that silver’s resistivity should be a bit below copper’s, aligning with the 1.64 × 10^-8 Ω·m answer.

Why Other Options Are Wrong:

0.16 × 10^-8 Ω·m is too small by a factor of 10; 16 × 10^-8 Ω·m and 164 × 10^-8 Ω·m are too large by 10× and 100× respectively; “None of these” is unnecessary since a correct value is provided.

Common Pitfalls:

Confusing resistivity (Ω·m) with conductivity (S/m); mixing up scientific notation; forgetting temperature dependence (resistivity rises with temperature for metals).

Final Answer:

1.64 × 10^-8 Ω·m