The Photoelectric Effect Essay

One of J.J. Thomson's most significant contributions to science, and thus to the study of atomic theory, was his discovery of the electron. Before the discovery of the electron, the atom was already associated with having electric charges-both positive and negative-but the idea of an electron existing as its own particle was unheard of. It was in 1897 when Thomson first conducted the beginning of his now famous experiment, in which he used a cathode ray tube to aid in his findings. A cathode ray tube, is a vacuum tube in which cathode rays, negatively charged particles, are produced at the cathode and travel through the vacuum, which is created when gas is extracted from the tube. J.J. Thomson discovered that in order to determine

A sodium ion (Na+) occurs when a sodium atom loses an electron and gains a positive charge

K. Paraphrase the three potential fates of the excited electron produced when a photon meets a chlorophyll molecule

In paragraph eleven of "Energy Story" it explains how electrons can work. The author states "Electrons can be made to move from one atom to another." and continues to "When

- I think that the electrons that are emitted from the cathode are emitted with a range of velocities (perhaps like a Boltzmann distribution where average speed clusters in the middle of the range).

When light is absorbed the electrons get excited and go into a higher energy level, so it move much more freely. This produces an electrical

The 1958 Nobel Prize in Physics was awarded to Pavel Alekseyevich Cherenkov, Ilya Frank and Igor Tamm for the discovery and the interpretation of the Cherenkov Effect. Cherenkov radiation is the electromagnetic radiation emitted by particles moving through a medium faster than the speed of light in the same medium. It was fist a detected by Soviet scientist Pavel Alekseyevich Cherenkov, of who the effect is named after and a theory was later developed by Ilya Frank and Igor Tamm. Cherenkov’s contributions still live on as an invaluable tool in today's nuclear and subatomic particle physics with examples that include a way to detect and quantify the characteristics of subatomic particles to analyzing high energy cosmic signals from the deepest regions of space. More down to earth uses consist of safety procedures for nuclear reactors and the detection of low concentration biomolecules in the sick and elderly.

Leonard Mandel, an extraordinary magnate optical scientist of his time, was a powerful voice on behalf of physics. He was the Lee DuBridge Professor of Physics and Optics at the University of Rochester: a masterful scientist, exemplary teacher, generous colleague, and beloved family man. He is perhaps one of the most amazing founding fathers of what we call; quantum optics, evolving into the revolution of so called “most exciting areas in science.” He trained society’s understanding of quantum mechanics and lasting ways through ingenious experiments that provided convincing demonstrations and precise tests of many of the most counterintuitive aspects of the quantum nature of light. Rarely has any one individual so intimately investigated and so dramatically advanced our understanding of the quantum mechanical nature of light.

Quantum effects provide additional sources of EMR, such as the transition of electrons to lower energy levels in an atom and black-body radiation. The energy of an individual photon is quantized and is greater for photons of higher frequency. This relationship is given by Planck's equation E = hν, where E is the energy per photon, ν is the frequency of the photon, and h is Planck's constant. A single gamma ray photon, for example, might carry ~100,000 times the energy of a single photon of visible light.

Walter Bothe took notice of the emission of neutral radiation from beryllium when bombarded it with alpha particles, and this lead to a later discovery of the abruption between hydrogen atoms and paraffin using electrical radiation.

Which voltages have an effect on the purple photons? The position of the hydrogen atom is the control variable and it will affect the electrons by how strong the electron is and how fast the electron travels, the firing of electrons is also a control variable throughout this experiment. The voltage of the battery will be the independent variable and will be changed from low to high voltage to observe the photons emitted. The number of purple photons emitted will be the dependent variable and it will be measured by counting the number of the photons emitted and the calculations will be made to estimate the final

During the cold winter of 1895, a German scientist by the name of Wilhelm Conrad Roentgen was working with a cathode-ray tube when he noticed nearby crystals were glowing. When Roentgen reached for the crystals he was amazed when the shadow cast on the crystal was not of his whole hand, but just his bones. Roentgen covered the tube with heavy black paper and saw that the crystals still glowed and the shadow of his hand bones still shown through, he then determined that a new ray was being emitted that could penetrate through thick materials. (1.) He later found that the rays could pass through most anything, but would cast a shadow of solid objects; these shadows could then be captured on film. Among the solid objects Roentgen shot with

Many centuries ago people did not need much energy. Back then, people used the sun or burned wood and straw for heat. People used the wind force in sails or horses to go anywhere in the world and used animals to do the work humans could not do. Although, humans did use simple machines that could ground grain, pump water, and even utilize steam power. Steam engines transformed over time and by the 18th century the modern steam engine, fueled by coal, could do the job of a team of horses. Since steam engines were much more favorable compared to air and wind power, steam engines were used to power factories and coal was used to heat up buildings.

Originally electricity and magnetism were thought of as two separate forces. This view changed, however, with the publication of James Clerk Maxwell's 1873Treatise on Electricity and Magnetism in which the interactions of positive and negative charges were shown to be regulated by one force. There are four main effects resulting from these interactions, all of which have been clearly demonstrated by experiments:

The ejected electrons hit another metal plate, the collector, which was connected to the cathode by a wire with a sensitive ammeter, to measure the current produced by the illumination. When he doubled the light intensity he noticed that the emitted electrons doubled. But the emitted electrons energy was not affected. He noticed that the the weaker electrons energy was the same as electrons emitted from a powerful oscillating field. He also did something else. He tested the photoelectric effect using different colors. The results were surprising, the energy of the photoelectrons did change with different colors, shorter wavelength and higher frequency light emitted photoelectrons with more energy.