Answer: its expansion is fairly uniform.
- A its expansion is fairly uniform
- B it conducts heat very poorly
- C it has a very low density
- D it freezes at a high point
Correct answer: A. its expansion is fairly uniform
Explanation: Mercury expands almost uniformly over a wide range and is opaque, so readings are reliable and visible.
During a phase change (melting or boiling), temperature stays constant while heat is absorbed entirely as latent heat (Q=mL); temperature only rises again once the substance is fully in its new phase.
Concept context
Temperature scales, thermal expansion, calorimetry, and the three modes of heat transfer including radiation laws.