Inert gas Inert gas An inert gas/noble gas is a gas which does not undergo chemical reactions under a set of given conditions. The noble gases often do not react with many substances, and were historically referred to as the inert gases. Inert gases are used generally to avoid unwanted chemical reactions degrading a sample. These undesirable chemical reactions are often oxidation and hydrolysis reactions with the oxygen and moisture in air. The term "inert gas" is context-dependent because several of the noble gases can be made to react under certain conditions. Purified argon and nitrogen gases are most commonly used as
Phase-out of incandescent light bulbs lives than incandescent bulbs. When bulbs are used infrequently, such as in little-used closets and attics, it may take a long time to compensate for the higher initial cost of the bulb. The overall energy savings from changing to more efficient lighting depends on the climate. In warm climates, efficient lighting has the additional energy-saving effect of reducing the amount of cooling required. In cold climates increased heating energy demand may offset some of the lighting energy saved with efficient lighting. A report published in January 2008 found that in Los Angeles, where incandescent lighting results in increased air conditioning,