Your SlideShare is downloading. ×
0
Atomic theory
Atomic theory
Atomic theory
Atomic theory
Atomic theory
Atomic theory
Atomic theory
Atomic theory
Atomic theory
Atomic theory
Atomic theory
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Atomic theory

449

Published on

Published in: Technology
1 Comment
0 Likes
Statistics
Notes
  • Be the first to like this

No Downloads
Views
Total Views
449
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
13
Comments
1
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. Atomic Theory : A Timeline<br />Melissa, Joe, Jake and Ryan<br />
  • 2. Democritus (400 BCE)<br />Greek philosopher<br />Theorist, not scientist<br />Atomic Theory: <br />All elements made of atoms<br />Atoms are indivisible, indestructible<br />
  • 3. Lavoisier (1777)<br />French chemist<br />Provided formula for the conservation of matter in chemical reactions<br />Distinguished between elements and compounds<br />
  • 4. John Dalton (1803)<br />English chemist and schoolteacher<br />Discovered atoms<br />Atomic Theory:<br />All elements composed of tiny, indivisible particles called atoms<br />Atoms of the same element are different from those of any other element<br />Atoms of diff. elements can mix physically or can chemically combine in simple whole-number ratios to form compounds<br />Chemical reactions occur when atoms are combined, separated, or rearranged<br />Atoms of one element are never changed into atoms of another element as a result of a chemical reaction<br />
  • 5. William Crookes (1870)<br />Created “Crooks’ Tube”<br />Demonstrated that cathode rays travel in straight lines and produce phosphorescence and heat when they strike certain materials<br />
  • 6. Eugene Goldstein (1886)<br />German physicist<br />Found rays traveling in the opposite of that of the cathode rays in a cathode ray tube<br />Called these “canal rays” (later renamed protons)<br />
  • 7. J. J. Thompson (1897)<br />Discovered electrons<br />Cathode ray tube experiments<br />Hypothesized that cathode rays are tiny, negatively charged particles moving at high speeds (electrons)<br />Measured the charge to mass ratio of the electron<br />Atomic Theory:<br />Plum pudding model – negatively charged particles contained in a positively charged matrix<br />
  • 8. Robert Millikan (1908)<br />American experimental physicist<br />Determined quantity of charge on an electron<br />Used Thompson’s charge to mass ratio to calculate the mass of the electron<br />Performed “oil-drop” experiments<br />
  • 9. Ernest Rutherford (1911)<br />English physicist and chemist<br />Gold foil experiments<br />Atomic Theory:<br />Atom is mostly empty space<br />Small, positively charged nucleus<br />Electrons move around outside of the nucleus<br />Created nuclear model<br />
  • 10. Neil Bohr<br />Danish physicist<br />Stated electrons moved around the nucleus in successive, large orbits<br />Also presented Bohr Atomic Model<br />Atoms absorb or admit radiation only when electrons abruptly jump between allowed, or stationary, states<br />
  • 11. James Chadwick (1932)<br />English physicist<br />Discovered neutrons<br />

×