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|Explanation of Matter and the Atomic Model Development|
_________________Model (600 BC; Greek) - all matter is made up of small indivisible particles called atoms. Some Greeks believe that the 4 main elements were: fire, water, air and earth and these made up all other matter was a combination of these.
______________ (early1600; French) had a fundamentally new approach in ways of scientific thinking. His search for certainty in the world was to based on the principle that everything should be doubted. As an intense student of mathematics he felt that everything (all truths) in nature could be explained through mathematics. He discovered analytical geometry that would important to Newton’s work.
______________ (~ 1600; English) thought that the basic approach to scientific knowledge should shift from deductive to inductive reasoning. Deductive reasoning starts with general laws and theories and develops specific truths; if A and B, then C. Inductive reasoning starts with observations and evidences and results in generalizations, that is, new theories and laws. This new way of thinking is the basis for the methods of science used today.
______________ (1687; English) was widely thought to be the greatest scientific mind ever. He publishing of Principia revolutionized the understanding of motion in what is now known as Newton’s Laws and includes one of the most influential equations, F=ma. He also invented the mathematics of calculus. Newton was a recluse and worked alone. He was always hesitant to publish his works because of his need for perfection in measurement and privacy.
______________Model (1803; English) did some fundamental chemistry with the ratios of which substances combined to form compounds. He stated some simple ideas about atoms. 1) they are ____________. 2) each element is composed of unique like atoms. 3) ______________are formed by joining 2 or more elements.
______________(1820; Danish) discovered electromagnetism. Perhaps the only major scientific discovery made in front of a class of his students, he noticed that a wire carrying a current deflected a needle of a compass, thereby founding the connection between __________ and ___________ fields.
______________(1831; English) discovered electromagnetic induction. His experiments revealed that an electrical current in a coil of wire would induce a current in a conductor inside the coil. This became the basis for modern motors and electrical power generators.
______________(1862-1873; Scottish) formulated Maxwell’s Equations, a set of equations that explains the phenomenon of electricity, magnetism, and light as an aspect of the single force of electromagnetism. This is considered the second great unification in physics after Newton’s Laws of Motion and his work helped set the stage for Einstein and modern quantum mechanics. His work also opened the possibility of radio. (He also was the first to take a color photograph in 1861.)
______________(1888; German) confirmed Maxwell’s Equations. He demonstrated that electromagnetism can exist as waves by building an apparatus that produced radio waves. He showed that the difference between various electromagnetic waves was in their frequency and wavelength. He also established the photoelectric effect latter explained by Einstein.
______________(1896; Danish) thought that atoms might exist of charged particles (electrons) that oscillated to produce light. He also proposed that moving objects have length contractions and time dilation, which were ideas latter used by Einstein’s work on relativity.
______________Model (1897; Scottish) discovered the ___________ charged electron during his famous ______________________experiment. He was a brash and not very well liked by his colleagues. His model was dubbed “plum pudding”, which represented electrons stuck in solid matter. He inferred that the solid matter was positively charged due to the fact that matter is generally neutral in charge.
______________(1900; German) discovered that matter absorbed heat energy and emitted light in quanta (or quantum, Latin for “how much”). This was the basis for what later would become quantum mechanics of how atoms work. He discovered one the fundamental constants of the universe: the frequency of a quanta light is directly proportional to its energy; E=hf, where h is defined as Planck’s constant. This energy is small, which makes light and matter appear continuous on a large scale, but on the atomic scale light and energy come only in discrete amounts (packets). (He was devastated later in life when his son was executed by the Nazi’s for an attempted murder of Hitler.)
______________ (1905, Swiss) explained the photoelectric effect that light energy comes in quanta later called photons. An electron is given off a metal surface when a photon of only a specific frequency (f or ν) and wavelength (λ) hits it.
He also stated his Theory of Special Relativity that the speed of light is a constant (3.0 x 108 m/s) and that matter and energy are two different forms of the same thing, _______, where c is the speed of light. He also elaborated on the time dilation and length contraction as being relative to velocity…at the speed of light mass is infinite and time stands still.
Einstein had rock star status in his time. He was not only known for theories, but for his philosophy on life, God, politics (he was a pacifist), and his one liners.
The last half of his life Einstein became quite separated from the science community. He was deeply troubled by the probability nature of quantum mechanics and Heisenberg’s uncertainty…He said, “God does not play dice with the universe.” He devoted this time to trying to unify all four of nature, strong and weak nuclear, electromagnetic and gravitational, but was not able to do so. His giants were Faraday, Maxwell, and Lorentz.
______________Model (1908; English) discovered the ___________ and that the atom was mostly ______________ with his famous ____________ experiment. He was a student of J.J. Thomson. He is regarded as the father of nuclear physics.
______________Model (1913; Danish) said that electrons are found in definite _______ around the nucleus at high speeds. Though definite orbits are not thought to be the case in today’s model, his model is still used as a depiction of the dispersion of electrons with energy levels. He was the ultimate experimentalist. He studied the spectra lines produced by hydrogen atoms and explained this phenomenon by the quantized nature of electron energies.
______________ (1916; American) accurately determine the mass of an electron in his famous _________________ experiment. Downward weight force of a small oil was balanced by the upward electric charge force and in doing so its mass was determined.
______________(1890; German) observed canal rays in a cathode ray tube that were later discovered by Rutherford as being positively charged particles he called _____________ in 1920.
______________(1920; French) earned his doctorate degree, which was approved by Einstein, for the idea of the wave-particle theory that units matter and light. He states that a moving particle (_________) of matter has with it an associated wavelength as a particle of light (_________). He based his work on that of Einstein and Planck. The energy of a particle is equal to hc/λ, where c is the speed of light and λ is its wavelength. This idea created a new field in physics known as wave-mechanics.
______________(1925; German) stated his exclusion principle that no two ____________ can occupy the same quantum state at the same time. If electrons are in the same orbital, then they will have different spin directions. He was a good friend of Heisenberg’s.
______________Model (1926; Austrian) stated that each electron in an atom is found inside a region called the electron ________. These are not specific orbits, but rather where electrons are likely to be at any point in time. This is based on principles known as wave or ___________________. He stated that electrons exist as a wave according to de Broglie’s equation and that it circles the nucleus in its energy level as a whole number of wavelengths. His conclusions are based on complicated equations known as the Schrödinger equations that help us understand the arrangements of electrons. He put forth this idea after extensive conversations with Einstein. This is the basis for the modern model of the atom today.
______________(1927; German) proposed his uncertainty principle that became a cornerstone of quantum mechanics. It states that the more precise the speed and momentum of an electron is known, the less precise its position at the time is known and vice-versa. This was a large change in a scientific way of thinking (and human knowledge in general) that science can answer all questions and know all things exactly through mathematics. He struggled mightily with this idea, which was resisted by Einstein.
The idea is that the act of observing alters the ______________! He headed up the nuclear program for the Nazi’s during WWII. (As a young man he was an accomplished piano and chess player.)
The Copenhagen interpretation (1927) was an agreement of the physics community concerning the wave-particle duality is the cornerstone of quantum mechanics. Niels Bohr’s wisdom as a senior in the community attempted to bring everyone together with his idea of ________________. It states that a single particle can behave as a wave or a particle, but never simultaneously…the greater the manifestation as a wave the weaker its particle nature and vice versa.
______________(1930, German) discovered the theoretical existence of the _____________, which is smaller than an electron and with neutral charge. He thought that one would be produced during beta nuclear decay when a neutron decayed into a proton. These particles have been thought to be produced in high quantities by nuclear fusion on the Sun and stream endlessly into space. Due to their size and lack of charge they can travel through hundreds and thousands of miles of matter with interacting with it. Many experiments have been set up to collect fleeting evidence on their possible existence. It is thought that these particles may make up a significant portion of mass in the universe.
These were also used to collide with protons in particle accelerators to discover the full range of subatomic particles theorized by Gell-Mann.
______________ (1930, American) discovered quantum electrodynamics (QED), which joined quantum mechanics and Einstein’s theory of special relativity. It describes the interactions of charged particles by exchanging photons of light.
______________(1932; English) confirmed the existence of the last massive part of the atom that did not have a charge. It was named the neutron. Rutherford had proposed its existence earlier. Chadwick’s work explained the existence of nuclear radiation through the existence of the neutron and began the age of modern nuclear physics.
_______________( 1940’s, American) formulated an understanding of QED to explain anomalies to allow for its practical use. He was famous for his Feynman diagrams that made the theory much easier to visualize. He was considered the most brilliant young mind of the Manhatan Project that developed the atomic bomb. He became the projects foremost troubleshooter and mathematician. Feynman was a great teacher and a very good speaker. His van at Cal Tech was covered with paintings of his diagrams.
_______________(1960’s, American) theorized the existence of many subatomic particles including the _______ that make up protons and neutrons. The existence of quarks and properties of particle spin were confirmed experimentally in 1969. There are believed to be 12 fundamental particles of nature, 4 boson particles that carry force, and an antiparticle for each with an opposite charge. Evidence for all has been confirmed through experimentation using particle accelerators except one…the graviton (Higgs-Boson). The large hadron collider (LHC) at CERN in Switzerland was built to find this elusive particle. Gell-Mann organized all these particles in a precise and understandable way. He turned a particle jungle into a particle zoo, so to speak.
________________(1995, American) showed that 5 versions of String Theory were actually one in the same. String theory has exceedingly elegant mathematics that describes matter as vibrating strings of energy. The frequency of vibration can be equated to each kind of subatomic particle. If the math is correct, there would be a total of 10 different dimensions of space and another for time. The theory also attempts to unify the four forces of nature…hence its nick name, the Theory of Everything. This theory is hoped to pull together relativity on the large scale and quantum mechanics on the subatomic scale to explain everything in the universe under one set of physical laws.
M-Theory grew out of String Theory and discusses that the universe is composed of tiny membranes that these strings of energy (matter) are tied to. It is theorized that a possible explanation for the relative weakness for the gravitational force would be that its string breaks free of a membrane and “floats” off into one of the unobservable dimensions of space (possibly another universe within our space).
Summary of quantum mechanics:
Applications due to an understanding of quantum mechanics:
Разработка математической модели и синтез наблюдателя состояния системы с прямым цифровым управлением
Не also discovered the Law of Universal Gravitation which states that "every particle of matter is attracted bу every other particle...
Доцент д-р инж. Румяна Петрова Статева Институт по инженерна химия, Българска Академия на Науките