Final answer:
The coefficient of cubical expansion of mercury at 1.8×10^-5°C^-1 indicates the change in volume per degree Celsius change in temperature. For thermometers, this affects the required spacing between temperature marks, considering both the expansion of mercury and potential expansion of the glass housing.
Step-by-step explanation:
The coefficient of cubical expansion of mercury is 1.8×10^-5°C^-1. This coefficient describes how the volume of mercury changes with temperature. Specifically, it means that for each degree Celsius increase in temperature, the volume of mercury will expand by 1.8×10^-5 times its original volume.
Considering a mercury thermometer with initial volume of 0.780 cm³ and an inside diameter of the tube of 0.130 mm:
- Neglecting the thermal expansion of the glass, the spacing between marks 1°C apart can be calculated using the coefficient of cubical expansion and the volume of the thermometer's bulb.
- If the thermometer is made of ordinary glass, additional calculations would be needed to account for the expansion of the glass itself.