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John Dalton
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Period: to
John Dalton
John Dalton discovered that all atoms of the same element had the same weight but atoms of different elements had different weights. He constructed a table of chemical elements basted on their atomic weights. He believed that atoms couldn’t be destroyed or created. Dalton also developed symbols for different atoms. References:Dowling, Helen 1993, Encyclopaedia of Science, Dorling Kindersley Limited, London.Goldsmith, Mike 2000, The Kingfisher Science Encyclopaedia, Kingfisher Publications Pl -
J.J. Thomson
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Period: to
J.J. Thomson
J.J Thomson discovered the electron in a series of experiments and invented the plum pudding model. The plum pudding model was where he imagined atoms consisted of a sphere of positive material and that negative particles were immersed at random like plums in a pudding. Thomson was able to change the line of a beam of cathode rays. He won the Nobel Prize in 1906 for his work. References:Goldsmith, Mike 2000, The Kingfisher Science Encyclopaedia, Kingfisher Publications Plc, London.Morton, A -
Marie Curie
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Period: to
Marie Curie
Marie Curie discovered several elements which were radioactive. Marie was the first scientist to use the term radioactivity. She confirmed that radioactive decay caused the transmutation of chemical elements and founded the modern science of radiochemistry. She won the Noble prize in 1911 for Chemistry. References:Aloian, Molly 2009, Atoms and Molecules, Crabtree Publishing Company, Australia. Trefil, James 2002, Cassell’s Laws of Nature, Cassel Wellington House, Slovenia.Ellyard, David 200 -
Ernest Rutherford
In 1908 Ernest Rutherford received a Nobel Prize. He made up his own atomic theory and created a famous experiment called the gold foil experiment. It showed that atoms had a positively charged nucleus. From this it proved that his theory was true and that atoms were made up of just empty space.References:
Morton, Alan 2005, Splitting the atom, Evans Brothers Limited, London.
"Rutherford - Atomic Theory." Rutherford - Atomic Theory. N.p., Accessed Web. 14 Sept. 2013. -
Henry Moseley
Bibliography:
"Famous Scientists." Science Blog RSS. N.p., n.d. Viewed, 12 Sept. 2013.
"Henry Gwyn Jeffreys Moseley (British Physicist)." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Viewed, 12 Sept. 2013. -
Niels Bohr
In 1913 Niels Bohr created a planetary model of the atom which is how he discovered electron shells. He believed that electrons in the orbits closer had less energy compared to the ones further away. In 1922 Bohr won a Nobel Prize for his atomic structure theory. References:Morton, Alan 2005, Splitting the atom, Evans Brothers Limited, London.Goldsmith, Mike 2000, The Kingfisher Science Encyclopaedia, Kingfisher Publications Plc, London. -
Period: to
Henry Moseley
Henry Moseley measured X-ray spectra of crystals. He related wavelength and atomic number aswell as knowing that atomic numbers were not arbitrary. He predicted missing elements in the period table and concluded that there were three unknown elements between aluminium and gold. -
Francis Aston
Francis Aston discovered the mass spectrometer which separates the isotopes of various elements. He formulated the whole number rule and measured the masses of neon atoms. From this Aston was able to find discover 212 more isotopes. He was awarded a Noble Prize in 1922.References:Dowling, Helen 1993, Encyclopaedia of Science, Dorling Kindersley Limited, London.Morton, Alan 2005, Splitting the atom, Evans Brothers Limited, London. -
Erwin Schrodinger
Erwin Schrodinger created an equation for waves. It is a mathematical equation which represents the probability of finding an electron in a specific position. He build upon Bohr’s thoughts and developed them further. Erwin Schrodinger is one of the pioneers of quantum mechanics. Schrodinger was awarded a Nobel Prize in 1933. References:Trefil, James 2002, Cassell’s Laws of Nature, Cassel Wellington House, Slovenia.Dowling, Helen 1993, Encyclopaedia of Science, Dorling Kindersley Limited, Lo -
James Chadwick
James Chadwick proved the existence of the neutron; the particle in the nucleus of an atom with no electrical charge. He conducted experiments such a s bombarding atoms of elements with alpha particles. He was awarded a Nobel prize in 1935.References:Dowling, Helen 1993, Encyclopaedia of Science, Dorling Kindersley Limited, London. Morton, Alan 2005, Splitting the atom, Evans Brothers Limited, London. -
Murray Gell-Mann
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Period: to
Murray Gell-Mann
Murray Gell-Mann first thought of the existence of the quark which means hat protons and neutrons have more fundamental particles. He created a table and left blank spaces in the spots where he thought another element existed but hadn’t been discovered. In 1969, Gell-Mann won the Nobel Prize for his quark theory. References:Morton, Alan 2005, Splitting the atom, Evans Brothers Limited, London.Aloian, Molly 2009, Atoms and Molecules, Crabtree Publishing Company, Australia.
