Given a scientific passage and an answer, generate a question for the given answer.

Example Input: Passage: Eggs are female gametes that form in the ovaries and are released into the fallopian tubes. Answer: eggs
Example Output: What are the female gametes that form in the ovaries?

Example Input: Passage: A vapor light also produces visible light by electroluminescence The bulb contains a small amount of solid sodium or mercury as well as a mixture of neon and argon gases. When an electric current passes through the gases, it causes the solid sodium or mercury to change to a gas and emit visible light. Sodium vapor lights, like the streetlight pictured in the Figure below , produce yellowish light. Mercury vapor lights produce bluish light. In addition to lighting city streets, vapor lights are used to light highways and stadiums. The bulbs are very bright and long lasting so they are a good choice for these places. Answer: gas
Example Output: When electricity is passed through solid sodium it changes into what and gives off light?

Example Input: Passage: Radioactivity is the ability of an atom to emit, or give off, charged particles and energy from the nucleus. The charged particles and energy are called by the general term radiation . Only unstable nuclei emit radiation. When they do, they gain or lose protons. Then the atoms become different elements. (Be careful not to confuse this radiation with electromagnetic radiation, which has to do with the light given off by atoms as they absorb and then emit energy. ). Answer: radioactivity
Example Output:
What is the ability of an atom to emit, or give off, charged particles and energy from the nucleus?