The physical property you measured is the boiling point of the liquid.
Therfore, if the liquid has a boiling point of 100°C, it turns from liquid state to vapor when you heat it up to 100°C.
To conclude, The liquid should be pure water. Because only pure water has a boiling point of 100°C, using this physical property, we can test whatever liquid ans see if it's pure water or not, this test is called the boiling point test.
