What property of matter does a hot spoon that was left in boiling soup illustrate?

The property of matter that a hot spoon that was left in boiling soup illustrates is thermal conductivity. Thermal conductivity is the ability of a material to transfer heat energy from one part of the material to another. In the case of the spoon, the heat from the boiling soup is transferred to the spoon through conduction. This causes the spoon to become hot, and it can then transfer the heat to your hand if you touch it.