What are some possible way's that tell you a physical change is taking place?
A physical change is a change in the appearance, or display, of a substance. No new substance is created in a physical change, as is in a chemical change. A change in texture, temperature, physical state (solid, liquid, or gas), color, or shape may be indicative that a physical change is occurring.
All phase changes (melting, freezing, condensation, evaporation, sublimation, and deposition) are physical changes. Phase changes have to do with temperature changes. Temperature is a measure of the amount of kinetic energy (energy of motion) within a substance. As molecules gain kinetic energy (and the temperature rises), the molecules expand and increase in volume.
If a color change is reversible, then it is a physical change. For example, painting a wall does not change the composition of the drywall. However, color changes also occur in chemical changes- such as the rusting of iron when exposed to oxygen.