A company is developing a temperature alarm, based on the schema below, that should close an electric circuit when the temperature rises above 150°C:

Temperature Alarm

	Linear coefficient of thermal expansion (x10^-6K^-1)	Volumetric mass density (kg/m³)	Melting point (°C)
Brass	13	8600	1000
Copper	17	8940	1100
Iron	11.8	7870	1500
Mercury	181	13540	-39
Polystyrene	70	1060	100
Steel	12	7800	1600

Based on available materials and their properties, choose materials for the temperature alarm that require the smallest temperature difference to do the task.

For Material 1: ___

For Material 2: ___