Our Solar System
12th grade essay on chemical bonds in our solar system. Well Researched!
Solar cells today are mostly made of silicon, one of the most common elements on Earth.
The crystalline silicon solar cell was one of the first types to be developed and it is still the most
common type in use today. They do not pollute the atmosphere and they leave behind no harmful
waste products. Photovoltaic cells work effectively even in cloudy weather and unlike solar
heaters, are more efficient at low temperatures. They do their job silently and there are no
moving parts to wear out. It is no wonder that one marvels on how such a device would
To understand how a solar cell works, it is necessary to go back to some basic atomic
concepts. In the simplest model of the atom, electrons orbit a central nucleus, composed of
protons and neutrons. each electron carries one negative charge and each proton one positive
charge. Neutrons carry no charge. Every atom has the same number of electrons as there are
protons, so, on the whole, it is electrically neutral. The electrons have discrete kinetic energy
levels, which increase with the orbital radius. When atoms bond together to form a solid, the
electron energy levels merge into bands. In electrical conductors, these bands are continuous but
in insulators and semiconductors there is an 'energy gap', in which no electron orbits can exist,
between the inner valence band and outer conduction band [Book 1]. Valence electrons help to
bind together the atoms in a solid by orbiting 2 adjacent nucleii, while conduction electrons,
being less closely bound to the nucleii, are free to move in response to an applied voltage or
electric field. The fewer conduction electrons there are, the higher the electrical resistivity of
Analyse and compare the information you have processed to assess the relative accuracy of the two models at predicting future astronomical events, such as the position of the planets.
... changing positions of the stars and planets during the ancient times. But the predictions made with Ptolemy's model of the planetary position and precessions of the equinoxes were not quite consistent with the best ...
This essay is about space exploration. specifically satillites,some of the Apollo missions and some of the mars missions.
... has the most interesting land surfaces in the solar system. Mars also has the largest mountain in the solar system, Olympus Mons, as well as a collection of canyons and craters. The accomplishments of humans ...
"Space Saving, Ready for Liftoff" My essay is about the contradictory issue of alloting more money for NASA and other space programs, or cutting back on their budgets.
... explorations of the Earth, Solar System, and universe are taught to students across the world ... catalyzed the communications satellite and electronic miniaturization revolutions, showed the entire planet the first colored pictures of Earth, placed satellites to transfer weather forecasts ...
... into the planet's magnetic fields. With such magnetic field, it sent Pioneer 10 out of the solar system! Then Pioneer flew all the way to Pluto's orbit. Pioneer ... a weather satellite. These satellites have sent back images of parts of the planets. The first satellite that could view the entire ...
... of the atom bomb. It was Ron Schaffner who developed this hypothesis after doing extensive research on V-2 rocket construction (Randle and Schmitt 120). Those who believe that the Roswell incident was not a secret rocket, balloon bomb, or weather ...
... because the tiny electric fields of these virtual pairs cause the atom's electron to shake in its orbit. Now ...
... gases. Chemical Rocket: This is the most common type of propulsion we use to enter orbit. The LHOX ... colonized the solar system our population will be somewhere to the order of 5 billion billion. Albert Eistein is the kind of human ...
Brief essay about the planet Mars. 596 words. Detailed about the surface of the planet, surroundings, and atmosphere.
... its orbit around the sun every two years. (Mars Science, 2000) Mars has many of the kinds of surface features that are common on ...