The term 'Noble Gas in Arc Lamps' refers to XENON, a chemical element with the symbol Xe and atomic number 54. XENON is a colorless, odorless, tasteless noble gas that is found in the Earth's atmosphere in trace amounts. It is used in arc lamps, which are high-intensity discharge lamps that produce light by creating an electric arc between two electrodes. XENON is used in these lamps because it produces a bright white light and has a long life span.