An environmental chamber constructed by Argonne's Materials Science Division allows researchers to watch materials as they grow step-by-step while interacting in elevated-temperature and reactive-gas environments. The first experiment in the chamber revealed information about how copper oxidizes at the nano-level and established a new basic model for understanding oxidation. The initial study found that clean copper surfaces are more resistant to oxidation than previously expected when exposed to oxygen. These findings could lead to improved electronic components. The chamber may also help researchers find better ways to produce hydrogen from hydrocarbons. Oxides can be protective, as when alumina forms on aluminum surfaces, or damaging, as when iron rusts and fails. Understanding these processes at the atomic level will allow researchers to manipulate oxidation to create better materials. The environmental chamber permits X-ray diffraction measurements at Argonne's Advanced Photon Source (APS) to reveal oxidation at the atomic level, including chemical and microstructural evolution, in a controlled environment over a sample's entire surface.