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Across 5. The _____ FTIR spectometers were large, expensive, and were found primarily in a few well-to-do research lab. 7. Who are the first one that invented on the interferometer? 8. _______ slit gives better resolution than its opposite type. 9. In dispersive type, ______ is a device that can disperse the spectrum from the light source into the specific narrow spectrum. 11. For dispersive type, these instruments separated the individual frequencies of energy emitted from infrared source using _____ which made up of NaCl. 14. When the molecule is exposed to infrared radiation, the molecule will vibrate, transferring energy from ground state level to ______ state level. 17. The two mirrors_____ both beams back to the beamsplitter where each of the two beams is again half reflected and half transmitted. 18. The absorption peak shows the ______ energy level. 19. Early work in IR absorption spectroscopy was used primarily for the structural identification of _______ materials. 20. The ________ is the heart of the interferometer. 21. Essentially, a half-silvered mirror, the beamsplitter reflects about half of an incident light beam while simultaneously ________ the remaining half

Down 1. The infrared source is _______ , emitting lightover a broad range of frequencies. 2. One half of this split light beam travels to the interferometer's moving mirror, while the other half travel to the interferometer's _______ mirror. 3. The molecule that are not infrared active is homonuclear _____ molecules because the dipole change cancelled each other. 4. In 1949, _________ Peter Fellgett used an interferometer to measure light from celestial bodies. 6. In 1892, Michelson had proposed the interference _______ for the wavelength determination of the meter. 10. The ______ __________ in the FTIR spectrosmeter is very simple : the interferometer requires two mirrors, an infrared light source, an infrared detector, and a beamsplitter 12. The vibrational motions of the atoms within a molecule are restricted by the bonds and the bond _______. 13. Infrared (IR) spectroscopy is the measurement of the absorption or _____ of infrared radiation by a material as function of wavelength. 15. Two output beams result: one travels to the _____ as the other travel to the source. 16. The first source of light for the earliest FTIR is ______.