The overhead projector in Tom's lab has a short circuit and gives him a shock every time he touches it. After a while Tom hesitates every time he is about to touch the overhead. In this example, the projector is the ___.

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.

the answer should be in the picture.