Name the Scientist
Name the scientist:
In 1804 this scientist created this atomic theory:
-All matter is composed of extremely small particles called atoms.
-Atoms of a given element are identical in size, mass, and other properties.
-Atoms of different elements differ in size, mass, and other properties.
-Atoms cannot be subdivided, created, or destroyed.
-Atoms of different elements can combine in simple whole number ratios to form chemical compounds.
-In chemical reactions, atoms are combined, separated, or rearranged.
While these concepts are still true today: Atoms of different elements differ in size, mass, and other properties, Atoms of different elements can combine in simple whole number ratios to form chemical compounds
Other concepts were proven wrong, for example
1. Atoms can further be subdivided into subatomic particles, 2. all atoms of an element are not identical in mass meaning that the elements can vary in the amount of neutrons they contain 3. using nuclear fission and fusion techniques, we can create or destroy atoms by changing them into other atoms therefore expanding and proving Dalton’s theory wrong
Who is John Dalton
(2) What did he discover:
Robert Millikan
-1911 he published the oil-drop experiment
His Oil-drop experiment included putting tiny oil droplets between two metal plates, some of the droplets picked up extra electrons. He kept messing with the plates and droplets until the droplets were suspended in mid air, he measured the electric field holding them in place to find the charge of each droplet.
What is the exact charge of an electron
(1.602 x 10^-19 coulombs)
Fill in the blank:
Published by Max Planck in 1900, Max discovered that:
“A [...?] is the smallest discrete unit (such as a particle) of a natural phenomenon in a system where the units are in a bound state.”
What is quanta
(1) Who is this scientist:
He published his results from the cathode ray experiments in 1897
Some of his experiments were:
-Cathode Ray experiments: He used cathode ray tubes to generate cathode rays. He saw that the rays are deflected by electric and magnetic fields, showing that they carry a negative charge. He concluded that there are streams of little negatively charged particles in all matter.
- Early mass spectrograph: used deflection paths to separate ion masses
-Experiments of Canal Rays and Isotopes: 1912 he sent a ionized neon through electric fields, the beam indeed up splitting, which means that neon contained two different masses
He was also responsible for discovering the electron and creating the plum pudding model
Who is JJ Thompson