Mercury(II) iodide is heated to convert it from its red low-temperature alpha form to its yellow high-temperature beta form.
solid state chemistry
When the beta form of mercury(II) iodide cools to below the transition temperature of 126°C, it returns to the red/orange alpha form.
When memory metal is bent, it deforms. When placed into hot water, the metal "remembers" its original shape.
An animation illustrates how peeling occurs between layers where bonding is weak in molybdenum disulfide.
A piece of glass is scratched with a diamond-tipped stylus, showing that diamond is harder than glass.
A piece of tape pressed against a sample of molybdenum sulfide will peel off layers of the sample. Additional tape can be used to cleave the peeled sample hundreds of times.