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. Also, during the early 1900s (1898-1907) a physicist named Ernest Rutherford worked on experiments to test current atom models. His experiments involved shooting rays of alpha particles (small positively charged particles) though very thin pieces of gold foil. Based on Thomson's model, Rutherford hypothesized that the alpha particles would travel through the gold foil mostly unaffected by the gold. He was right.
In the 1700’s, Antoine Lavoiser wrote the first extensive list of elements and categorized them into metals and non-metals . Johann Wolfgang Döbereiner and Alexandre-Emile Béguyer de Chancourtois also tried to classify the elements in the mid 1800’s but were not extremely successful. Döbereiner classified elements into triads with elements with similar properties while Béguyer de Chancourtoiswas the first to notice that when elements are arranged by their atomic weights, groups of elements ... ... middle of paper ... ...he same regardless of the type of atom. He then concluded that atoms consist of tiny, negatively charged particles. He, like Chadwick, received a Nobel prize for his work in 1906 .
In 1898, Marie Curie (Polish physicist) and Pierre Curie (French physicist) were one of the first scientists to isolate radium and polonium from pitchblende (uraninite). Henri Becquerel received a Nobel Prize for his work, finding radioactivity in uranium. Wilhelm Konrad Rontgen also received a Nobel Prize for discovering the X-ray. These breakthroughs aforementioned were why he turned his attention to radioactivity. His ability to work creatively, not only by himself, but also with other associates, whom most were already established in the field of science.
1803 John Dalton British chemist and physicist John Dalton theorised that matter is composed of spherical atoms (that are in motion) of different weights and are combined in ratios by weight. 1896 Wilhelm Rontgen Discovered that certain chemicals glowed when exposed to cathode rays. These chemicals were special because they weren’t deflected by the magnetic field produced in the cathode ray tube (which was built by Sir William Crookes in 1870). He Called these X-rays. 1896 Henri Becquerel Accidentally discovered spontaneous radioactivity.
With the help of Geiger he found the number of alpha particles emitted per second by a gram of radium. He was also able to confirm that alpha particles cause a faint but discrete flash when striking luminescent zinc sulfide screen. These great accomplishments are all overshadowed by Rutherford's famous Gold Foil experiment which revolutionized the atomic model. This experiment was Rutherford's most notable achievement. It not only disproved Thomson's atomic model but also paved the way for such discoveries as the atomic bomb and nuclear power.
Dalton soon came up with ‘weight’ theories of the atom a discovered that hydrogen was the lightest. In 1813 Jons Jakob Berzelius created a system using the Latin words for the element to represent that element. In 1860 the chemist of Europe had their first international Chemical Congress to discuss the matter. They theory that prevailed was Cannizzaro theory. John Thomson was born in 1856, and is recognised as the British scientist who discovered and identified the electron.
John Dalton John Dalton was a great help to modern day chemistry. He was born in 1766 in the small town of Eaglesfield, Cumbria, NW England in the UK. He was a chemist that stated an atomic theory of matter, which is now the theory of modern day chemistry. Besides his theories, he published the first major book of the studies of color blindness; which affected him. The book was published in 1794.
He first studied medicine but was later sent to athens and became a philosophiest under a man named plato. Alchemy is what became th... ... middle of paper ... ... each charge had a mass ratio of 1.759E8 coulombs per gram. He concluded that all atoms have this negative charge (through more experiments) and he renamed the cathode rays electrons. His model of the atom showed a sphere of positively charged material with negative electrons stuck in it. Thomson received the 1906 Nobel Prize in physics.
Most had no concept of what an atom bomb was or why it was so powerful. The story of the atomic bomb opens with a series of new discoveries in physics that began near the turn of the century. The term classical is applied to the physics that scientists developed prior to that time (Cohen, 17). Much of it came from the work of the Father of Physics, the great seventeenth-century English scholar, Sir Isaac Newton. Newton was a scientific genius.
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.