In this Activity, students observe and compare the behavior of three lightsticks that are exposed to three different temperature ranges (cold, room temperature, and hot). The Activity could be used early in the school year to give students practice in making detailed observations and devising reasonable explanations for those observations. It illustrates the use of qualitative vs.
In this Activity, students observe UV-sensitive beads that have been melted into flat disks, explore the temperature behavior of the disks, and then use the disks to investigate the effectiveness of different sunscreens. The Activity shows applications of chemistry in the real world.
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.
An acidified iron(III) solution is added to iodide solution to see if oxidation to triiodide will occur.