The “Elephant Toothpaste” experiment is a very popular, albeit messy chemistry demonstration. To carry out this experiment, place a 250 mL graduated cylinder on something that you wouldn’t mind getting messy.
Happy New Year! Did you know that 2015 is the International Year of Light (IYL)? IYL is a “global initiative adopted by the United Nations to raise awareness of how optical technologies promote sustainable development and provide solutions to worldwide challenges in energy, education, agriculture, communications and health1”. IYL is sponsored by several organizations with interests in science and science education, including the European Physical Society, the Institute of Physics, the American Physical Society, and the American Institute of Physics. You can find several lesson plans, videos and other educational resources on the IYL website2.
In this Activity, students prepare cyanotype paper and use it to "photograph" different items using sunlight. This Activity demonstrates catalysis of chemical reactions by ultraviolet (UV) light using one of the earliest photographic processes, the cyanotype process. It is useful as an introduction to the damaging effects of UV radiation on living organisms and the role of sunscreens.
When acidic dichromate and iodide solutions are mixed, no immediate reaction takes place. Addition of iron(II) solution brings about rapid formation of brown triiodide.