A liquid-in-glass thermometer is calibrated with a Celsius scale from −20∘C-20^\circ\text{C}−20∘C to 120∘C120^\circ\text{C}120∘C. Which points define the two standard fixed points used to calibrate this Celsius thermometer?
The lowest mark (−20∘C-20^\circ\text{C}−20∘C) and the highest mark (120∘C120^\circ\text{C}120∘C)
The temperature of melting pure ice (0∘C0^\circ\text{C}0∘C) and the temperature of steam from boiling pure water (100∘C100^\circ\text{C}100∘C) at standard atmospheric pressure
The beginning and end of the liquid column at the current temperature
The lower and upper ends of the glass tube containing the liquid
528 exam-style questions on CIE IGCSE Physics 2.2 Thermal properties and temperature, covering 2.2.1 Thermal expansion of solids, liquids and gases, 2.2.2a Internal energy and temperature, 2.2.2b Specific heat capacity, 2.2.3a Melting, boiling, condensation and solidification, 2.2.3b Evaporation, and 2.2.3c Cooling by evaporation. Each one has a worked solution and a mark scheme showing where the marks go.