Other+Scientists

Democritus
[] Summarize his theory of the atom. democritus theory was that everything is made up of atoms. atoms is a physical thing and atoms can never be destroyed.atoms can differ in mass ,size or in color. Who were his critics and what theories were postulated to challenge his? the two men the were critics were two men by the name parmedies and zeno they argument was the void theory which is nothing can be their James Chadwick [] What did he discover and when? Why did it take so long to make this discovery?

What did he discover and when? In 1932, James Chadwick discovered the neutron (subatomic particle with no net electric charge.) He performed a series of experiments at the University of Cambridge showing that the previous gamma ray hypothesis was untenable. He said that it may be that the new radiation had uncharged particles in the mass of the proton. He then demoed another series of experiments verifying his hypothesis. Why did it take so long to make this discovery? It took 12 years to make this discovery because there were previous scientists with different hypothesis’. This started in 1920 when Ernest Rutherford suggested the possible existence of the neutron. Then in 1930, Viktor Ambartsumian and Dmitri Ivanenko proved that some neutral particles must be present besides the protons. A year later, Walther Bothe and Herbert Becker found that if the energetic alpha particles emitted from polonium fell on certain light elements thus penetrating radiation was produced (thought to be gamma radiation but later proved by Irene Joliot Curie and Frederic Joliot that if this unknown radiation fell on paraffin it ejected protons of very high energy.) That’s when in 1932, Chadwick proved otherwise.

Louis DeBroglie [] Explain his contribution to the wave-particle duality theory.

In 1924, Louis DeBroglie took Einstein's E=mc2 and Planck's E=hv equations and made his own equation for wavelength. Wavelength= h/mv h=6.626068 × 10-34 J s; m=mass in kg; v=velocity in m/s.

Robert Millikan [] What is Millikan’s major contribution? Watch the video that animates the Oil Drop Experiment. Let’s pretend that you have to explain what happened in this experiment to a class of fourth graders. How did the experiment work and what did Millikan find out? You cannot use any big fancy words!!! Robert's major contribution is him doing the oil drop experiment in 1909 to measure the charge of electron. He used a known electric field and he determined the charge on the oil drops in mechanical equilibrium. Oil drop experiment was a test acted out by a man named Robert Millikan in 1909 to igure out the size of the charge on a particle called electron. He also figured out that there was a smallest unit charge. Millikan put a charge on a really small drop of oil and measured how strong an electric field had to be in order to prevent the oil drop from falling down. Erwin Schrodinger and Werner Heisenberg [] State Heisenberg’s Uncertainty Principle --

Heisenberg uncertainly principle states that the more we know about where a particle is right now, the less we know about how fast it's going and the direction that it's going.

Werner Heisenberg’s uncertainty principle was that certain pairs of variables cannot be measured at the same time and be accurate. He also found that it is possible to measure the position or the momentum of a position or the momentum of a substance particle within an atom. But it is not possible to measure both at the same time because the process messes up what is being measured.

Explain Schrodinger’s contribution to the model of the atom. Erwin Schrodingers contribution to the model of the atom is he made the equation

witch is the description of the electrons given by a wave function witch explains the amplitude of the electron at any time. Wave functions are the answer to his equation. His equation requires calculus.

Find visuals that show what Schrodinger’s s, p, d, and f energy sublevels look like.