Thermochromism: Mercury(II) Iodide - Temperature Increases
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
Thermochromism: Mercury(II) Iodide - Temperature Decreases
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.
Memory Metal - Demonstration
When memory metal is bent, it deforms. When placed into hot water, the metal "remembers" its original shape.
Memory Metal - Animation
An animation shows how memory metal can be deformed then go back to its original shape.
Hardness of Solid Substances - Peeling Layers of Molybdenum Disulfide - Animation
An animation illustrates how peeling occurs between layers where bonding is weak in molybdenum disulfide.
Hardness of Solid Substances - Grinding Lead
Lead is a relatively soft metal that can be flattened.
Hardness of Solid Substances - Diamond Scratching Glass
A piece of glass is scratched with a diamond-tipped stylus, showing that diamond is harder than glass.
Hardness of Solid Substances - Shattering a Silicon Wafer
A silicon wafer is flexed until the wafer shatters.
Hardness of Solid Substances - Peeling Layers of Molybdenum Disulfide
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.
Hardness of Solid Substances - Cutting Lithium
Lithium, a very soft metal, can be cut with a knife.