Description : What must happen a substance to appear black what must happen to all wavelengths of light?
Last Answer : A substance that appears black (in a lighted room) is absorbingall of the visible light that hits it, leaving no visible light toreflect off of it to your eye. So it's absorbing visible light ... 's happening to theinfra-red or ultraviolet hitting it. For that, you need to usedifferent detectors.)