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.
The hydrogen halides are compounds that contain hydrogen attached to one of the halogens (HF, HCl, HBr, and HI). These compounds are all colorless gases, which are soluble in water. Up to 512 mL of HCl gas can dissolve in a single mL of water at 0 o C and 1 atm, for example.