Light from the sun

Ozone, O3, is found in trace quantities in the upper atmosphere where it is believed to be formed by the photochemical dissociation of oxygen molecules by the intense ultra-violet light from the sun ... 

Historically, the first spectroscopic studies involved characterizing the emission of visible light from the sun, from flames, and from salts added to flames. Our survey of spectroscopy, however, begins with absorption because it is the more important technique in modern analytical spectroscopy. 

The object interacts with a flowing medium. Sails interact with the wind, rafts float downstream, a spacecraft is propelled by the stream of photons (light) from the sun. This is more of a channeling type of propulsion m that the propelled object deflects the flowing stream m such a way that it is forced to move in desired direction. 

A rainbow, usually seen when the sun comes out after a rainfall, is the result of the dispersion of visible light (from the sun) into its component colors. The water t droplets act as prisms. ... 

In the seventeenth century, Sir Isaac Newton showed that visible (white) light from the Sun can be broken down into its various ccdor components by a prism. The spectrum obtained is continuous it contains essentially all wavelengths between 400 and 700 nm. 

Ultraviolet light from the sun is the most common hair-bleaching agent. Lemon juice is sometimes added to speed up the process of reducing the double bonds in hair pigments to single bonds. 

Because CFCs are highly resistant to chemical attack, they are stable in the lower atmosphere, where they can exist for up to 100 years. This stability gives CFCs time to diffuse up through the troposphere and into the stratosphere. There, CFCs absorb short-wavelength ultraviolet light from the sun that breaks carbon-chlorine... 

We have seen already how photons of UV light from the sun can cause burning of the skin. UV photons often cause bonds to cleave,... 

The top of a bookcase or tabletop exposed to the sun soon shows a thin surface of dust. It s not just that sunlight makes the dust more visible rather, it is because light from the sun actually promotes the collection of the dust. 

We have already seen how, on the microscopic level, the vibrational energies of bonds are quantized in a similar manner to the way the energies required for electronic excitation are quantized. For this reason, irradiation with an infrared light from the sun or a lamp results in a photon absorption, and the bonds vibrate, which we experience as the sensation of heat. 

Solar cells do not use most of the energy of sunlight. Light from the sun has an average temperature of about 6300°K. The Helmholtz ratio of sunlight is about 95%. This means that theoretically it should be possible to convert 95% of the radiant-energy to electricity. 

The net effect of aU the chemistry is that light from the sun is used to drive life processes. Carbon dioxide taken up in photosynthesis is released in respiration. 

We have seen that Boyle s conception of chemistry was a very mechanical one and this attitude is nowhere more evident than in his view on the composition of the atmosphere. He was much impressed by the presence of many extraneous exhalations from the earth, water, minerals, vegetables, and animals, c, but these made up only a very small part of the atmosphere itself The second sort of particles, even more subtle than the first, consist of the magnetical steams. .. and the innumerable particles of light from the sun and other stars. But the third set of particles are those, which are not only for a while, by manifest outward agents, made elastical, but are permanently so, and on that account may be styled perennial air. 5 In short, Boyles concept of the atmosphere is that of an intrinsically elastic air which carries in it the various steams and smoakes from a variety of sources. It is these adventitious ingredients that are responsible for any seemingly chemical involvement of the atmosphere. For Boyle, the air itself is characterized by its elasticity and has no chemical function. 

The greenhouse effect in Earth s atmosphere. Visible light from the sun is absorbed by the ground, which then emits infrared radiation. Carbon dioxide, water vapor, and other greenhouse gases in the atmosphere absorb and reemit heat that would otherwise be radiated from Earth into space. 

ASTROCHEMISTRY. Application of radioastronomy (microwave spectroscopy) to determination of the existence of chemical entities in the gas clouds of interstellar space and of elements and compounds in celestial bodies, including their atmospheres. Such data aie obtained from spectrographic study of the light from the sun and stars, from analysis of meteorites, and from actual samples from the moon. Hydrogen is by far the most abundant element in interstellar space, with helium a distant second. 

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