Fig. 2.1 shows a simplified diagram of a type of thermometer called a platinum resistance thermometer. The glass tube is immersed in the environment for which the temperature is to be determined. The resistance between the terminals X and Y is measured. Fig. 2.2 shows the variation of the resistivity ρ of platinum with thermodynamic temperature T.

Explain how Fig. 2.2 shows that platinum is a suitable metal for use in a resistance thermometer.