- Index, Washington (Wikipedia)
Index (Lushootseed: x̌əx̌aʔusalʔtxʷ) is a town in Snohomish County, Washington, United States. The population was 178 at the 2010 census.
- Xenon (Wikipedia)
Xenon is a chemical element; it has symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth’s atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as the formation of xenon hexafluoroplatinate, the first noble gas compound to be synthesized.