Atom Timeline by Kaitlyn Howard https://padlet.com/howardkaitlyne/ngsqq3ir2nqw en-us 2018-10-04 16:26:50 UTC 2023-05-15 00:58:57 UTC hello@padlet.com Democritus howardkaitlyne https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289247857
  • According to Democritus atomic theory, the universe and all matter obey the following principles: Everything is composed of “atoms”, which are physically, but not geometrically, indivisible. Between atoms, there lies empty space. Atoms are indestructible. 
  •  It was developed in the fifth century B.C.            
  •  The theory was developed in Greece 
    • ]]>     2018-10-04 16:28:50 UTC https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289247857     howardkaitlyne https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289255787 2018-10-04 16:41:26 UTC https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289255787 howardkaitlyne https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289255886 2018-10-04 16:41:32 UTC https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289255886 howardkaitlyne https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289255974 2018-10-04 16:41:35 UTC https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289255974 howardkaitlyne https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289256269 2018-10-04 16:42:00 UTC https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289256269 Ernest Rutherford howardkaitlyne https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289258855
  • Rutherford designed an experiment to use the alpha particles emitted by a radioactive element as probes to the unseen world of atomic structure.The model described the atom as a tiny, dense, positively charged core called a nucleus, in which nearly all the mass is concentrated, around which the light, negative constituents, called electrons, circulate at some distance, much like plants revolving around the sun.
  • The theory was developed in 1911
  • It was developed in Manchester
    • ]]>     2018-10-04 16:46:14 UTC https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289258855     Erwin Schrodinger howardkaitlyne https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289271204
  • He proposed that electrons are arranged in concentric circular orbits around the nucleus.  These are the 4 principals of his theory:
    •  Electrons occupy only certain orbits around the nucleus. Those orbits are stable and are called "stationary" orbits.
    • Each orbit has an energy associated with it. The orbit nearest the nucleus has an energy of E1, the next orbit E2, etc.
    • Energy is absorbed when an electron jumps from a lower orbit to a higher one and energy is emitted when an electron falls from a higher orbit to a lower orbit.
    • The energy and frequency of light emitted or absorbed can be calculated by using the difference between the two orbital energies.
       2. He developed the theory in 1926
    3.He developed it in Austria 
    ]]>     2018-10-04 17:05:07 UTC https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289271204     John Dalton howardkaitlyne https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289711217
  • John Dalton proposed that all matter is composed of very small things which he called atoms. This was not a completely new concept as the ancient Greeks (notably Democritus) had proposed that all matter is composed of small, indivisible (cannot be divided) objects.
  • He developed his theory in 1803
  • he developed his theory at a library in Manchester.
    • ]]>     2018-10-05 16:27:09 UTC https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289711217     joseph Thomson howardkaitlyne https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289716902
  • His model was the earliest theoretical description of the inner structure of atoms. Thomson held that atoms are uniform spheres of positively charged matter in which electrons are embedded. 
  • He developed the theory in 1897
  • e developed his theory in England 
    • ]]>     2018-10-05 16:38:55 UTC https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289716902     Niels Bohr howardkaitlyne https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289722134
  • Niels Bohr proposed a theory for the hydrogen atom based on quantum theory that energy is transferred only in certain well defined quantities. Electrons should move around the nucleus but only in prescribed orbits. When jumping from one orbit to another with lower energy, a light quantum is emitted.
  • He developed his theory in 1913
  • He developed it in Norway 
    • ]]>     2018-10-05 16:49:35 UTC https://padlet.com/howardkaitlyne/ngsqq3ir2nqw/wish/289722134