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- 41: Ozone
- Ozone Ozone (O3) is a molecule consisting of three oxygen atoms, similar to the oxygen we breathe (O2), however oxygen consists of only two oxygen atoms. In the stratosphere, a region high up in the upper atmosphere, light rays are responsible for the breaking down of oxygen (O2), breathable oxygen into its two separate oxygen atoms. Lone oxygen atoms are markedly reactive. When a lone oxygen atom comes into contact with a breathable oxygen molecule (O2) it combines to form ozone (O3). The ozone layer is a small residual amount ...
- 42: Lasers And Their Applications
- ... to the sum of the individual amplitudes of the original waves. Stimulated emission is the process that the laser works on, which was first proposed by Albert Einstein in 1917. When a sufficient number of atoms, either gas solid or liquid, absorb energy so that they are in an excited state of higher energy stimulated emission can occur. Light of a specific wavelength can produce more light with the same phase ... coherent. Stimulated emission amplifies the coherency of this radiation and gives the radiation a very narrow beam spread. The combination of light amplification and stimulated emission creates a laser. Laser light is coherent because the atoms are stimulated to emit waves of light that are in phase creating constructive interference producing a powerful and intense laser light. The emitted light is monochromatic, meaning only one wavelength, and one directional. For a ... when electrons in high energy levels are more numerous than electrons in lower energy levels), in the gain medium. Finally two mirrors that form a resonator cavity where small units of energy released from the atoms called photons move back and forth between the mirrors triggering more stimulated emissions. The energy of a photon is calculated using the equation: E =hv where E is the energy of a photon, h ...
- 43: Lasers 2
- ... 1960 the American physicist Theodore Maiman observed the first laser action in solid ruby. HOW A LASER WORKS A laser is made up of several basic components. One is called active medium, which consists of atoms of a gas, molecules in a liquid, ions in a crystal, or any of several other possibilities. Another component consists of some method of introducing energy into the active medium, such as a flash lamp. The third basic component is a pair of mirrors placed on either side of the active meduim, one of which transmits part of the radiation that strikes it. Atoms initially in a lower state are raised to the upper state by energy from a flash lamp or some other pumping source. Some of these atoms emit light in random directions. Light traveling vertical to the mirrors stays within the active medium long enough to stimulate emission from other atoms. Light traveling in other directions are soon lost. Some light ...
- 44: Benzene
- ... 176 degrees F). In the past benzene was obtained from the distillation of coal in the absence of air. Today most benzene is made syntheticallyfrom petroleum products. The benzene is a closed ring of six atoms connected by bonds that resonatebetween single and double bonds; each carbon is also bound to a single atom. Benzene isinsoluble in water but mixes in all proportions with organic . Benzene is itself an excellentsolvent for ... degree of unsaturation, but benzene does not display the reactivity characteristic of such compounds. In 1865, German chemist Friedrich August Kekule von Stradonitz proposed thatbenzene is structurally a planar hexagon in which the six carbon atoms are joined byalternating single and double bonds. Because this simplistic structure could not accountfor all of the unique properties of benzene and its derivatives, German chemist JohannesThiele suggested in 1899 that the bonds between carbon atoms exhibit resonance. That is,each bond oscillates between being a double and a single bond (see aromatic compounds). In modern chemistry, benzene is generally considered to have six identical carbon-carbonbonds, each lying somewhere ...
- 45: Lasers and Their Uses
- ... chosen this topic to write about. The term laser is an acronym. It stands for "light amplification by stimulated emission of radiation". They produce a narrow, intense beam of coherent light. In a laser the atoms or molecules of a crystal, like ruby or garnet-or of a gas, liquid, or other substance-are excited so that more of them are at higher energy levels than are at lower energy levels ... photon of the same frequency, in phase with and in the same direction as the bombarding photon. This process is called stimulated emission. The bombarding photon of the emitted photon may then strike other excited atoms, stimulating further emission of photons, all of the same frequency and phase. This process produces a sudden burst of coherent radiation as all the atoms discharge in a rapid chain reaction. The light beam produces is usually pencil thin and maintains its size and direction over very long distances. Lasers vary greatly in the way they look and what ...
- 46: Technology Has Influenced Our
- ... as opposed to how it came to be. In the study of the origin of the universe how the universes were created is the main focus. In the 1900's it was generally thought that atoms were similar to tiny balls. There were studies that showed that atoms could be placed into a category according to one like in a periodic table. This suggested that atoms were not fundamental. Furthermore, experiments which "looked" into an atom using probes showed that atoms had structure and were not just penetrable balls. These experiments helped scientists determine that atoms had a positive, dense ...
- 47: Atomic Bomb
- ... would have been unstoppable. A nuclear weapon harnesses the power of the atom with a process known as an Uncontrollable Fission Reaction. In this process, a neutron (a subatomic particle found in the nucleus of atoms) is bombarded with the nucleus of a radioactive atom, such as Uranium or Plutonium. This causes the nucleus of the radioactive atom to become unstable, and split into two new atoms. To stabilize the new atoms, more neutrons are released, which move on to bombard with another radioactive nucleus. The energy released comes from the binding energy (the energy required to keep the nucleus together) in the nucleus of the ...
- 48: Radioactive Wastes
- ... manner that isolation from the biosphere is assured until they have decayed to innocuous levels. If this is not done, the world could face severe physical problems to living species living on this planet. Some atoms can disintegrate spontaneously. As they do, they emit ionizing radiation. Atoms having this property are called radioactive. By far the greatest number of uses for radioactivity in Canada relate not to the fission, but to the decay of radioactive materials - radioisotopes. These are unstable atoms that emit energy for a period of time that varies with the isotope. During this active period, while the atoms are 'decaying' to a stable state their energies can be used according to the ...
- 49: Atomic Bomb 5
- ... would have been unstoppable. A nuclear weapon harnesses the power of the atom with a process known as an Uncontrollable Fission Reaction. In this process, a neutron (a subatomic particle found in the nucleus of atoms) is bombarded with the nucleus of a radioactive atom, such as Uranium or Plutonium. This causes the nucleus of the radioactive atom to become unstable, and split into two new atoms. To stabilize the new atoms, more neutrons are released, which move on to bombard with another radioactive nucleus. The energy released comes from the binding energy (the energy required to keep the nucleus together) in the nucleus of the ...
- 50: Plato Vs. Materialists
- ... properties. One example of accounting for this is that thought is only the function of a material brain and caused by electrical connections within the brain tissue. Materialism states that all matter is made of atoms, which are limitless in number, and the different appearance of objects are a result of the difference in size and shape of atoms and by the different ways these atoms combine. When the conclusions of nuclear physicists are taken into account, especially their studies on atomic particles, the problem of the reality of the material world and how much can be known about it ...
Search results 41 - 50 of 278 matching essays
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