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Search results 121 - 130 of 278 matching essays
- 121: The Cosmos: Creation
- ... established the existence of other galaxies. He noted that the light from these galaxies was shifted toward the red. That is it's wavelength was longer than that of the light emitted from the corresponding atoms in the lab. Furthermore he found that the farther away the galaxy was the more it was shifted toward the red end of the spectrum. Hubble attributed this shift to the doppler effect. Hubble saw ... the fabric of the universe changed in a fundamental way. The most recent occurred when the universe was about 500,000 years old, about 14,999,500,000 years ago. After 500,000 years permanent atoms started to form. Before 500,000 years matter existed as loose electrons and nuclei in a state called plasma. Moving back in time the next freezing occurred at about three minutes. This was when nuclei ...
- 122: Ocean Environment
- ... changes the characteristics of incoming waves. This interaction between the waves and the bottom results in the beach face having an everlasting wave pattern. Everything in the universe is composed of extremely small paritcles called atoms, which are often bonded together to form molecules. Molecules are formed as the result fo the transfer of electrons between atoms. The complete loss and gain of electrons results in the formation of ionic molecules, which have completely positive and negative vegions. Unequal sharing of electrons, on the other hand, characterizes the polar covalent molecules, which ...
- 123: Our Radiant Planet- Depletion of the Ozone Layer
- Our Radiant Planet- Depletion of the Ozone Layer Ozone is a relatively unstable form of molecular oxygen containing three oxygen atoms produced when upper-atmosphere oxygen molecules are split by ultra violet light. Stratospheric ozone is found in a broad band, extending generally from 15 to 35km above the earth. Although the ozone layer is surprisingly ... C radiation) in a reaction that liberates an atom of chlorine, which destroys ozone by oxidising with the Ozone molecules, forming Cl-O and Oxygen. One atom of chlorine can destroy 10,000 ozone molecules! Atoms containing bromine, nitrous oxide, and hydrogen oxide radicals are also primarily dangerous. As a result, the Ozone in the stratosphere has been reduced to such an extent that ozone holes are appearing around the globe ...
- 124: The History of Carbon
- ... and uses energy from the sun in the form of light. Six molecules of carbon dioxide combine with six molecules of water to form one molecule of glucose (sugar). The glucose molecule consists of six atoms of carbon, twelve of hydrogen, and six of oxygen. Six oxygen molecules, consisting of two oxygen atoms each, are also produced and are discharged into the atmosphere unless the plant needs energy to live. In that case, the oxygen combines with the glucose immediately, releasing six molecules of carbon dioxide and six ...
- 125: Mini-Research
- ... be 1.0073 amu. This became known as a proton. NEUTRON- In 1932, James Chadwick detected the third of the basic parts of an atom. He showed that uncharged particles, or neutrons, are emitted when atoms of other elements are bombarded with high-velocity helium atoms with all electrons remored, or an alpha particle. Neutrons were determined to have a mass of 1.0087 amu. They are unstable outside of an atom and slowly degenerate to form protons and electrons.
- 126: Fission or Fusion
- ... initiated by the absorption of one neutron in uranium-235 releases about 2.5 neutrons, on the average, from the split nuclei. The neutrons released in this manner quickly cause the fission of two more atoms, thereby releasing four or more additional neutrons and initiating a self-sustaining series of nuclear fissions, or a chain reaction, which results in continuous release of nuclear energy. Naturally occurring uranium contains only 0.71 ... needed to heat and confine the gas. A subsequent major problem is the capture of this energy and its conversion to electricity. At temperatures of even 100,000° C (180,000° F), all the hydrogen atoms are fully ionized. The gas consists of an electrically neutral assemblage of positively charged nuclei and negatively charged free electrons. This state of matter is called a plasma. A plasma hot enough for fusion cannot ...
- 127: Chloroflourocarbons
- ... cans were sold in America. The hopes of a seemingly perfect refrigerant were diminished in the late 1960's when scientists studied the decomposition of CFCs in the atmosphere. What they found was startling. Chlorine atoms are released as the CFCs decompose, thus destroying the Ozone (O3) atoms in the high stratosphere. It became clear that human usage of CF2Cl2 and CFCl3, and similar chemicals were causing a negative impact on the chemistry of the high altitude air. When CFCs and other ozone ...
- 128: Rubidium
- ... high heat transfer coefficient. When rubidium gas is placed ion a sealed glass cell along with an inert gas, it becomes a rubidium-gas cell clock. Because of the consistent and accurate vibrations of its atoms it is a very accurate clock. Rubidium is used as an electrolyte for low temperature storage batteries for use in the polar regions of the Earth. Rubidium and selenium are used to make photoelectric cells (electric eyes). When light hits these elements, electrons are knocked loose from the outer shells of their atoms. These free electrons can carry electrical current. Rubidium is also used as a getter to remove gasses in vacuum tubes. Photoelectric cells can be used to send a beam across a driveway or a door ...
- 129: The Big Bang
- ... then electrons, and finally neutrinos. After about an hour, the temperature had dropped below a billion degrees, and protons and neutrons combined and formed hydrogen, deuterium, helium. In a billion years, this cloud of energy, atoms, and neutrinos had cooled enough for galaxies to form. The expanding cloud cooled still further until today, its temperature is a couple of degrees above absolute zero. In the future, the universe may end up ... expanding infinitely into the darkness. This space will become even emptier, as the fundamental particles of matter age, and decay through time. As the years stretch on into infinity, nothing will remain. A few primitive atoms such as positrons and electrons will be orbiting each other at distances of hundreds of astronomical units.7 These particles will spiral slowly toward each other until touching, and they will vanish in the last ...
- 130: The Big Bang
- ... electrons, and finally neutrinos. After about an hour, the temperature had dropped below a billion degrees, and protons and neutrons combined and formed hydrogen, deuterium, and helium. In a billion years, this cloud of energy, atoms, and neutrinos had cooled enough for galaxies to form. The expanding cloud cooled still further, until today its temperature is a couple of degrees above absolute zero. In the future, the universe may end up ... expanding infinitely into the darkness. This space will become even emptier, as the fundamental particles of matter age, and decay through time. As the years stretch on into infinity, nothing will remain. A few primitive atoms such as positrons and electrons will be orbiting each other at distances of hundreds of astronomical units. These particles will spiral slowly toward each other until touching, and they will vanish in the last flash ...
Search results 121 - 130 of 278 matching essays
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