There are three states of water: liquid, gas and solid, which is the phenomenon of water and the different forms of the essence of water (chemical essence is H2O).

2 content and form:

The chemical elements of water-hydrogen and oxygen-are the components of water; The chemical structure of water-the way water molecules are formed-exists in the form of water.

3 Causality:

Liquid water changes shape with the change of temperature, that is, it becomes solid (ice) or gas (water vapor). In this process, temperature is the cause of change, while ice or water vapor is the result of change.

4 inevitability and contingency:

The change of water temperature will inevitably lead to the change of interaction between water molecules, but it is accidental when the water temperature reaches 100 degrees Celsius. For example, the boiling point of water is not always 100 degrees Celsius.

5 Reality and Possibility:

There is a glass of liquid water in front of us, which is realistic, but it contains the possibility of becoming solid water (ice) or gaseous water (steam).