What is the maximum number of states of matter?

What is the maximum number of states of matter?

Three
Four
Five
Variable
This question was previously asked in
UPSC CDS-1 – 2017
The maximum number of states of matter is variable. While the most commonly known states are solid, liquid, gas, plasma, and Bose-Einstein condensate, the concept of “state of matter” or “phase” is broad. Under different conditions of temperature, pressure, magnetic field, etc., substances can exist in numerous distinct phases (e.g., superfluids, superconductors, various crystalline structures, liquid crystals, fermionic condensates, etc.). The number of possible states depends on the substance and the range of conditions considered, making it a variable quantity rather than a fixed small number.
Beyond the classical solid, liquid, gas, and plasma states, physics recognizes many other distinct states (phases) of matter. The number of these states is not fixed and can vary depending on the substance and the environmental conditions, as well as how a “state” is defined.
Phase diagrams illustrate the different phases of a substance under varying temperature and pressure. These diagrams can show multiple solid phases, indicating that even within one traditional state (solid), there can be different distinct states depending on the conditions.