Challenge it

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Across
  1. 6. range of wavelengths or frequencies over which electromagnetic radiation extends
  2. 8. heat
Down
  1. 1. light can be seen
  2. 2. shorter than that of a normal radio wave but longer than those of infrared radiation
  3. 3. Invisible rays that are part of the energy that comes from the sun
  4. 4. a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei
  5. 5. form of electromagnetic radiation, similar to visible light.
  6. 7. smallest wave length