1. Atomic and Molecular Structure a. Students know how to relate the position of an element in the periodic table to its atomic number and atomic mass. The Periodic Table organizes elements by their atomic number - from hydrogen (1) to whatever is the highest one currently known (>105). It is arranged so that similiar members fall in a list such as Chlorine Bromine etc.. The average atomic weight is usually shown with each element‚ but due to isotopes (caused buy nuclear varations)
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Atomic structure: scientists 1. Democritus: 1st person to think of atom (500 BCE)- philosopher Atom is the smallest piece of an element that has same properties as the element. 2. Lavisier: Law of conservation of mass/ matter • Mass can’t be created or destroy; same amount of stuff 3. Joseph Proust: Law of constant composition (law of definite Proportions) • A compound is always made of the same elements in the same ratio. 4. John Dalton: English school teacher who derived the atomic theory
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The Atomic Model has changed over time‚ as the years‚ decades‚ and centuries go by we get a better understanding of the atom and what it looks like. The Atomic Model has changed drastically based on the understanding we have on it‚ each new model has added more information to what we know about it‚ making it easier for scientists and the world to understand. The Atomic Model is a very important part of Science and Chemistry‚ it helps explain the structure and what is inside the atom‚ the particle
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United States of America was faced with some crucial choices in the spring of 1945. At this point‚ Harry S Truman had to decide whether to invade Japan’s mainland or to retaliate by air via the atomic bomb. America had been fighting in the war for the three exhausting years‚ losing a large number of soldiers. With Japan’s relentlessness‚ it was unclear how many more lives would be lost and how many more months the battle would be fought. The use of the atomic bomb on Japan was indeed necessary due
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a physics professor at Columbia University‚ suggests a clock could be made from a technique he developed in the 1930’s called atomic beam magnetic resonance. 1949 Using Rabi’s technique‚ NIST (then the National Bureau of Standards) announces the world’s first atomic clock using the ammonia molecule as the source of vibrations. 1952 NIST announces the first atomic clock using cesium atoms as the vibration source. This clock is named NBS-1. 1954 NBS-1 is moved to NIST’s new laboratories
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History of the Atomic Model Just as we once believed that the earth was flat‚ our understanding of the atom was once extremely limited. As time passes‚ we begin to discover more and more about the world we live in. We have come to know much about the atom over the past two hundred years through the work of numerous brilliant scientists. Throughout history‚ scientists have come up with many experiments and atomic models to explain the atoms all around us‚ all leading up to our modern understanding
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proton and an electron? (1) They have the same masses and the same charges. (2) They have the same masses and different charges. (3) They have different masses and the same charges. (4) They have different masses and different charges. 3 The atomic mass of an element is the weighted average of the masses of (1) its two most abundant isotopes (3) all of its naturally occurring isotopes (2) its two least abundant isotopes (4) all of its radioactive isotopes 4 Which statement is true about
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The History of Atomic Theory Atomos: Not to Be Cut The atomic model has changed throughout the centuries starting in 400 BC‚ when it looked like a billiard ball. Democritus: 400 BC The question: Can matter be divided into smaller particles? Or can it be infinitely divided? Matter can be divided into the smallest piece‚he named it “atomos”: not to be cut. Said that atoms were small‚ hard particles that were all made of the same material but were different shapes and sizes. Atoms were
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The Bomb That Rapidly Changed The World The atomic bomb is a bomb that rapidly releases energy causing destructive damage through heat. The atomic bomb dropped on Japan was not needed it was an evil act and was unnecessary. It was undoubtedly not required to drop a 4-ton barbaric weapon that is equivalent to 5 million dollars on another country. The United States Military had already launched a sea blockade that consisted of a submarine campaign before the bomb was dropped. It was cutting food
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Understanding the Decision to Drop the Bomb on Hiroshima and Nagasaki http://csis.org/blog/understandingdecisiondropbombhiroshimaandnagasaki Why is the source reliable and useful? This source is provided by CSIS Center for Strategic and International Studies. It is a prominent American think tank based in Washington‚ D.C.‚ in the United States. The center conducts policy studies and strategic analyses of political‚ economic and security issues throughout the world. So the arti
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