(Q).
Q: Amines are weak bases due to the presence of a lone pair of what on the nitrogen atom? Read this paragraph and choose the correct option from the provided answers: Amines are weak bases due to the presence of a lone pair of electrons on the nitrogen atom. This lone pair can attract the hydrogen atom from a water molecule, causing the bond between it and the oxygen atom to break. The resultant products are the conjugate acid of the amine and the hydroxide ion. Choices: - protons - nuclei - atoms - electrons A:
(A).
electrons

(Q).
Q: Light emitted by atoms is polychromaticcontaining more than one of these? Read this paragraph and choose the correct option from the provided answers: Lasers Most light emitted by atoms is polychromaticcontaining more than one wavelength. In contrast, lasers (from light amplification by stimulated emission of radiation) emitmonochromatic light a single wavelength only. Lasers have many applications in fiber-optic telecommunications, the reading and recording of compact discs (CDs) and digital video discs (DVDs), steel cutting, and supermarket checkout scanners. Laser beams are generated by the same general phenomenon that gives rise to emission spectra, with one difference: only a single excited state is produced, which in principle results in only a single frequency of emitted light. In practice, however, inexpensive commercial lasers actually emit light with a very narrow range of wavelengths. How a CD player uses a laser to read a CD. Inside a CD is a flat, light-reflecting layer called "land. " On the land are many "pits" recorded in a spiral-shaped track. (From the laser's point of view, pits are actually the "bumps" shown here because the master disc with pits is duplicated negatively, turning the pits into bumps. ) Pits have the same light-reflecting surface as land, but there are differences in the frequencies of the reflected light in the pit and the land, making light reflected by pits relatively dark compared with light reflected by land. Choices: - gravity - filter - weight - wavelength A:
(A).
wavelength

(Q).
Q: What is another term for nearsightedness? Read this paragraph and choose the correct option from the provided answers: Nearsightedness, or myopia, is the condition in which nearby objects are seen clearly, but distant objects appear blurry. The Figure below shows how it occurs. The eyeball is longer (from front to back) than normal. This causes images to be focused in front of the retina instead of on the retina. Myopia can be corrected with concave lenses. The lenses focus images farther back in the eye, so they fall on the retina instead of in front of it. Choices: - hypoxia - astigmatism - anemia - myopia A:
(A).
myopia