- Atoms of two or more elements can combine in constant ratios to form new substances. In the late 1800s a man named J. J. Thomson did some experiments, who's results did not agree with Dalton's Atomic Theory. Thomson passed electricity though gases, my his experiments, he theorized the existence negatively charged subatomic particles he called electrons. From this theory Thomson created a model of a atom which had the electrons placed evenly inside the atoms. In the early 1900s a Japanese scientist named H. Nagaoka designed an atom model as a large sphere surrounded by a ring of negatively charged electrons.
Mainly because of this device he made he was able to state that electric discharge was created when current goes through a low pressure gas, the discharge color can be determined by the type of gas in the t... ... middle of paper ... ... In 1897 Thomson brought together all the evidence to finally say that the cathode rays are negatively charged particles and they are much less massive than atoms and also they the same when made from different elements. He discovered the electron as we know now, but the name given to it by Thomson was the subatomic particle. An American scientist Robert Millikan had done experiments in the 1906. An experiment called Millikan oil drop as we call it today.
One of the next most recognized people involved in the progression of atomic theory was J.J. Thompson. Thompson had researched the work of William Crookes whose research concluded that cathode rays were deflected by magnetic fields. Thompson elaborated on this conclusion and found that cathode rays were also deflected by an electric field. With much experimentation Thompson theorized that although the atom was made up of small particles it was not the same indestructible model proposed by Dalton. A man named Milikin determined the mass of an electron to be 0 amu and the relative charge to be negative 1.
Reactor breeders show great promise in nuclear waste, but are it enough to convince the nation? Introduction Nuclear knowledge has existed for a long time. Nuclear Engineering U.S. Department of Energy relates, ―By 1900, the physicists knew the atom contains large quantities of energy‖ (par 11). Many others formed good theories, such as Ernest Rutherford and Einstein’s contribution with his equation E=mc^2. In 1934 a physicist known as Enrico Fermi conducted an experiment that resulted in the splitting of atoms.
In 1895, Wilhelm Röntgen found that when he put an electric current in an evacuated tube, x-rays were produced. Rontgen called this ionizing radiation because the x-rays were a result of electrons coming off of an atom making the atom an ion. In the following year a man named Henri Becquerel took an ore containing uranium and radium, pitchblende, and saw that it caused to darken a sheet of silver salts on a piece of glass finding alpha particles and beta radiation. In 1902, Ernest Rutherford found that he could change what element an atom is by getting an alpha or beta particle to come off of the nucleus. Seventeen years later he proved this by making a nitrogen atom into oxygen from shooting alpha particles off of radium.
Plutonium is able to maintain its solid state until very high temperatures, melting at six hundred and forty degrees Celsius, and boiling at three thousand four hundred and sixty degrees. The density of Plutonium, at twenty degrees centigrade, is 19.86 grams per cubic centimeter. Plutonium was discovered, in the laboratory, by Glenn Theodore Seaborg, and his associate Edward M. McMillan. The two shared the Nobel prize in 1951 for their discoveries of Plutonium, Americium (Am), Curium (Cm), Berkelium (Bk), and Californium (Cf). In addition, Seaborg later contributed to the discovery of three more radioactive elements, Einsteinium (Es), Mendelevium (Md), and Nobelium (No).
Stars owe their existence to the force of gravity. Stars are created from the thinly spread atoms of dust and gas that swirl throughout space. The atoms clump together into dense clouds that eventually collapse under their own gravity. Other forces counteract the gravity. The dust and cloud grows steadily hotter until a nuclear furnace ignites creating a bright shining star.
John Dalton is most recognized for his findings, which later is known as "the atomic theory". The atomic theory is the theory of the nature of matter. It states that: "all matter is composed of atoms." Lord Kelvin James Joule worked with Lord Kelvin on experiments, which later became know as the Joule-Thomson Effect: Lord Kelvin was a well known Mathematical Physicist. The well known "Lord Kelvin" born as William Thomson, June 26 in 1824 and later died December 17 in 1907.
Lorentz Force: eVB=m(v2/r) =eV(Bh-Be), this accounts for the centripetal force by making it equal the magnetic force acting on the mercury (electron) beam. Same variables as equation (1) except for r is the radius curvature of the mercury beam, Bh is the Helmholtz coil magnetic field and Be is the Earth’s magnetic field. This equation along with the kinetic energy equation leads to the derivation of... ... middle of paper ... ...hamber to view photons released by de-exciting mercury atoms and the physical phenomenon of the way charged particles are affected in a magnetic field in this lab allowed for the manipulation of current and voltage to produce a value of the charge to mass ratio of an electron. The experimental value was determined to be 3.97x1010 C/Kg, while the theoretical value is 1.76x1011 C/Kg. Thus, this experiment showed accurate results with minor sources of error, determined to be: the affect of the Earth’s magnetic field and imprecise measurements.
This work catapulted his career as an experimentalist and captivated the minds of many great physicists. After discovering these particles by using an electrometer to measure electric current created by radiation, Rutherford wished to leave radio-chemistry behind and get back into the physics world; he began by using his latest discovery to learn about atoms and their structures. Before he could do this, he needed to learn more about the behavior and structure of the alpha particles. Ernest and his partner Hans Geiger developed a machine that could aid in the counting of alpha particles called the Geiger Counter. The men applied a voltage to a metal cylinder with a wire running through its center, then allowed particles to pass through a small window where they created gas ions by colliding with gasses.