The Washington tree, located in the Giant Forest Grove in Sequoia National Park provides a good example of the aforementioned phenomena. This tree was the second largest tree in the world (only the General Sherman tree was larger) until just a few years ago.
A halogen is a representative element from group VII in the periodic table. More specifically, Fluorine, Chlorine, Bromine, Iodine, and Astatine. Astatine is a very unstable radionuclide so is not normally dealt with. A halide is a chemical compound of halogens bonded to more electro positive elements.
A halogen is a monovalent element on the Periodic Table, which easily forms negative ions. There are 5 such halogens - fluorine, chlorine, bromine, iodine, and astatine - but only iodine and bromine are used in lamps. In a halogen light bulb, the filament wears down, shedding tungsten atoms over time.