How Did Thomson Discover The Atom?

Integrated Physics and Chemistry – Unit 2: The Structure of Matter Experiment: Atomic Structure In this experiment, you will have a chance to test the hypothesis that Ernest Rutherford used when determining the size of the nucleus. In his "gold foil experiment," Rutherford shot alpha particles at gold atoms. Once he realized that the alpha particles were hitting a concentrated positive mass, he developed the nuclear model of the atom. Next, he set out to determine the relative size of the nucleus compared to the rest of the atom. He reasoned that the smaller the nucleus, the less likely it was to be hit by an alpha particle. This led to a simple comparative ratio:

History of an Atom In this day and age, almost every educated middle school student would be able to sketch and label a given diagram of an atom. However, still to this day, not one human has seen what an atom looks like. Our current atomic model, the same one in

Before Rutherford’s Geiger-Marsden experiment the most popular model of the atom was the “plum pudding model” developed in 1904 by the person who also discovered the electron in 1897, J.J. Thompson. It was the most common model of the atom and stated that electrons (plum) floated around with

1897: James Johnson Thomson • Thomson discovered the electron. He used a cathode ray tube (an electron gun) with a magnet and discovered that the green beam it emitted was made up of negatively charged particles. Thomson then determined that these negatively charged electrons needed something positive to balance them out. (Born, 2014)

During the early 1940’s atomic science had just began to mature. Many people were exploring the powerful mystery of the atom. Two of those people were Eugene Booth and John Dunning, who, in 1941, synthesized uranium-235. Immense scientific growth followed their contribution, since it allowed for nuclear fission (Griffith). In the years following this discovery, nuclear science took a turn. Once only used as a constructive power source, atoms began being explored for their destructive power. In 1942 the United States government funded the Manhattan Project that sole goal was to develop a nuclear bomb. The initiator for this endeavor was surprisingly the famous scientist Albert Einstein. He wrote to Franklin D. Roosevelt , and tipped him off

What is an atom? An atom is the basic building block of everything. An atom is made of electrons protons and neutrons and the number of protons determines the element. Back in the 1800’s this whole idea was unknown. In the 1800’s steam was starting to power everything. It became important to know how steam works, so you can learn to use it more effectively. It was this idea that drove Dalton to research the atom.

After researching about astronomy and the discovery of Uranus by William Herschel in 1781, I learned a lot about Uranus. I think one of the most shocking things about the discovery of Uranus was that William Herschel wasn’t even a professional astronomer, he was actually a musician. He did have

His Parents Richard Feynman's discoveries helped make the atomic bomb. He was one of the most important people in recent times. As a child his parent aspired for him to become scientist. Because of that Richard Feynman's was a successful physicist in his adult life. Richards father (Melville Feynman) had

This information has not always been know to man though. Thankfully scientist such as J.J Thompson, Ernest Rutherford, and James Chadwick were able to perform experiments to shed more light on what the atom was made of. The electron was first found in 1897 by J.J Thompson; shortly after in 1911 the nucleus was discovered by Rutherford, leading to him later discovering the proton in 1919. Before James Chadwick discovered the neutron many scientists believed that there were additional protons in the nucleus, along with the equal number of electrons to cancel out the additional charge. Then in 1920 Rutherford thought that the protons plus the electrons made up a new particle but it was never confirmed. After a few years of study John Chadwick was able to discover the neutron through unidentified radiation experiments, one experiment in particular caught his eye Frédéric and Irène Joliot-Curie had studied unidentified radiation from beryllium as it hit a paraffin wax target. This experiment encouraged Chadwick to do some of his own experiments in 1932 which made him believe that the radiation ejected from beryllium was in fact a neutral particle about the mass of a proton. He also tried many other targets besides the paraffin wax, these included helium, nitrogen, and lithium. These experiments led Chadwick to find the the mass of the new particle was more than the proton, he also found out that the neutrons have no

Ch 1 Each different scientist made an impact in some way to the origins of an atom. Lucretius’s work, De Rerum Natura, was the basis for many future scientists. Robert Boyle was a very religious man and people believed that was the reason for him not marrying. Boyle constructed the idea that the air was made up of different particles with each having different functions. Huygens first thought of the idea that waves of light moved in a spherical shape. His wave theory is still used today along with Maxwell’s electromagnetic theory. Isaac Newton is highly popular for his theory of gravity. Bernoulli began with the idea of the kinetic theory of gases in his work, Hydrodynamics. Newton gave the image to a lot of scientists after him of what an

The atomic model that was accepted by the scientific community before Rutherford's experiment consisted of a group of positive charge surrounded by electrons to balance the negative charge of the electrons. In Rutherford's experiment, he found that there was a center to atoms, later to be named the nucleus. Rutherford created his own model after stating that Thompson's was incorrect.

Upon securing victory in Japan, whatever relief the American people felt from winning WWII was tempered by the realization that science had just created a weapon that could wipe nations off the face of the earth. The atomic bomb, if other countries obtained the technology, could bring about a nuclear holocaust. This fear of technology could have stymied scientific progress post WWII. However, going into the Cold War, people once again put their hope in science and looked at scientific progress as a measure of whether they were beating the Soviet Union. This was most evident in the space race, as both countries invested large amounts of resources into their space programs. Somehow, both countries had decided that scientific research for going into space would be the frontier upon which they would fight their indirect war.

Leucippus and Democritus discovered the atom(doc. 1). Ernest Rutherford split the atom and discovered that the atom is made of smaller particles and that atoms have a positively charged nucleus and largely empty space(doc. 1). Without Leucippus and Democritus, no one could expand on the idea of the atom and without Rutherford no one would have thought of the nucleus and what is inside the atom(doc. 1). Atoms are so small

J.J Thomson He discovered the electron and experimented by testing the electric discharge in a high vacuum cathode ray tube. (Nobel Lectures.1967)

There are many Scientist that contributed in the investigation of the atom which are: 1- John Dalton 2- Sir William Crookes 3- Wilhelm Rontgen 4- J.J Thomson 5- Max Planck 6- Albert Einstein 7- Ernest Rutherford 8- Neils Bohr 9- James Chadwick 10-Otto Hahn The Discovery of the Atom first came from the Greeks which made a theory “The idea that all matter is made up of tiny, indivisible particles, or atoms, is believed to have originated with the Greek philosopher Leucippus of Miletus and his student Democritus of Abdera in the 5th century B.C. (The word atom comes from the Greek word atomos, which means “indivisible.”)” (InfoPlease Atomic theory)