Why are changes of state considered to be physical?

Related questions

• How can changes of state be explained by the particle theory?
• How do changes in state involve exchanges of energy?
• How do changes of state establish equilibrium?
• How do changes of state relate to the kinetic theory?
• How do the laws of conservation apply to changes of state?
• What changes in state are endothermic?
• Why are sublimation and deposition unusual changes of state?
• Why do changes of states matter?
• Which state of matter undergoes changes in volume most easily?
• What is the primary factor that determines if an element is a solid, gas, or liquid at room temperature?