Across
- 2. the chemical element of atomic number 13, a light silvery-gray metal.
- 6. a solid substance that has a conductivity
- 7. the intentional introduction of impurities into an intrinsic semiconductor for the purpose of modulating
- 10. crossing the atlantic
- 11. the branch of science concerned with the investigation and measurement of spectra produced when matter interacts with or emits electromagnetic radiation.
- 12. a unit of frequency equal to one billion hertz
- 14. the branch of physical science that deals with the relations between heat and other forms of energy (such as mechanical, electrical, or chemical energy), and, by extension, of the relationships between all forms of energy.
- 15. a fact or situation that is observed to exist or happen, especially one whose cause or explanation is in question
- 17. (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.
- 20. a device that generates an intense beam of coherent monochromatic light (or other electromagnetic radiation) by stimulated emission of photons from excited atoms or molecules.
- 21. a semiconductor device with three connections, capable of amplification in addition to rectification.
- 22. an electromagnetic wave with a wavelength in the range 0.001–0.3 m
- 23. he chemical element of atomic number 2, an inert gas which is the lightest member of the noble gas series.
- 24. the basic unit of a chemical element.
- 25. suggested that light itself was made up not of waves, but of packets of energy (later named photons); the higher the frequency of the light, the more energetic the photon
Down
- 1. the use of thin flexible fibers of glass or other transparent solids to transmit light signals, chiefly for telecommunications
- 3. a general agreement.
- 4. he quality of allowing light to pass through so that objects behind can be distinctly seen.
- 5. a colorless gas with a characteristic pungent smell. It dissolves in water to give a strongly alkaline solution.
- 8. the limit of a person's mental perception, experience, or interest.
- 9. an electronic device for increasing the amplitude of electrical signals, used chiefly in sound reproduction.
- 13. the chemical element of atomic number 81
- 16. one million hertz
- 18. relating to the interrelation of electric currents or fields and magnetic fields.
- 19. an expert in or student of physics