instruction:
Given a scientific passage and an answer, generate a question for the given answer.
question:
Passage: A lens that causes the light rays to bend away from its axis is called a diverging lens. Ray tracing is the technique of graphically determining the paths that light rays take. The image in which light rays from one point on the object actually cross at the location of the image and can be projected onto a screen, a piece of film, or the retina of an eye is called a real image. Thin lens equations are. Answer: diverging lens
answer:
What do you call a lens that causes the light rays to bend away from its axis?

question:
Passage: Chemical cells are found in batteries. They produce voltage by means of chemical reactions. Chemical cells have two electrodes, which are strips of different materials, such as zinc and carbon. The electrodes are suspended in an electrolyte. This is a substance that contains free ions, which can carry electric current. The electrolyte may be either a paste, in which case the cell is called a dry cell, or a liquid, in which case the cell is called a wet cell. Flashlight batteries contain dry cells. Car batteries contain wet cells. Answer: chemical
answer:
Batteries produce voltage through what type of reaction?

question:
Passage: In an electrically neutral atom, the number of protons equals the number of electrons. Answer: they are equal
answer:
How does the number of protons compare to the number of electrons in an electrically neutral atom?