Conceptual representation of ‘thermal equilibrium’ caused contacting two objects with different temperatures.

Timeline	Symbol	Examples of visualization	Code of textbooks
1) two objects of different temperatures are separated, 2) two objects of different temperatures come into contact, 3) the temperatures of the two objects become the same.	The qualitative height of the thermometer's column shows the high temperature, low temperature, and temperature at thermal equilibrium.		15i
	1) White symbolizes high-temperature dumplings and blue symbolizes low-temperature plates 2) The red symbolizes a dumpling with a low-temperature and the green symbolizes a plate with a high-temperature 3) A yellow symbolizes dumpling and dish that have reached thermal equilibrium		15h