Consider a 1-mm-diameter surface area of carbon (graphite). Calculate how many atoms would exist in energy levels from which they could emit radiation at wave- lengths shorter than 700 nm (visible light and shorter wavelengths) for surface temperatures of 300 K, 1,000 K, and 5,000 K when the solid is in thermal equilib- rium at those temperatures. Assume that only those atoms within a depth of 10 nm of the material surface can emit observable radiation.