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Across
  1. 3. the branch of science concerned with the nature and properties of matter and energy.
  2. 6. strength or energy as an attribute of physical action or movement.
  3. 7. (of electromagnetic radiation) having a wavelength shorter than that of the violet end of the visible spectrum but longer than that of X-rays.
  4. 10. a vehicle's capacity to gain speed within a short time.
  5. 11. (of electromagnetic radiation) having a wavelength just greater than that of the red end of the visible light spectrum but less than that of microwaves. Infrared radiation has a wavelength from about 800 nm to 1 mm, and is emitted particularly by heated objects.
  6. 12. the action or process of moving or being moved.
Down
  1. 1. reduction in speed or rate.
  2. 2. an amount of space between two things or people.
  3. 4. the throwing back by a body or surface of light, heat, or sound without absorbing it.
  4. 5. the rate at which someone or something is able to move or operate.
  5. 8. the fourth letter of the Greek alphabet ( Δ, δ ), transliterated as ‘d’.
  6. 9. the third letter of the Greek alphabet ( Γ, γ ), transliterated as ‘g.’.