History Of The Atom Flashcards
Key ideas of the atom have been proposed by …
Dalton
Thompson
Rutherford
Bohr
Who were the first to have ideas about the atom?
Ancient Greeks
What did Dalton figure from his experiments?
Substances were made up of atoms which were tiny and hard shaped like spheres.
Each chemical element had its own atoms that differed from others in mass.
Atoms could not be divided or split.
Atoms rearranged themselves in chemical reactions.
Why are daltons ideas still useful today?
They help to visualise elements, compounds and molecules.
What year did dalton make his discoveries ?
1803
What year did Thompson make his discoveries?
1897
What was the main thing that Thompson discovered?
The electron
How did Thompson discover the electron?
Bonus question ! - how did he do the experiment ?
He did experiments on the beams of particles and found they that were attracted to a positive charge showing that they must be negatively charged.
Bonus ! - he experimented by applying high voltages to gases at low pressure.
Which scientist proposed the plum pudding model ?
JJ Thompson
Explain the plum pudding model of an atom
This model suggested that the tiny electrons must be embedded in a cloud of positive charge.
The positive charge being the sponge and the electrons being the bits of plum in a plum pudding.
Why did Daltons idea of atoms being unable to split or divide have to be revised?
Thompson noticed during his experiment that the electrons he discovered had to have come from inside the tube he was experimenting with meaning that they must have split from the atoms inside the tube.
Who made discoveries in 1911
Rutherford
Who carried out Rutherfords experiments under his directions ?
His university students Geiger and marsden
What was the most important thing that Rutherford discovered?
Nucleus
What was the atomic model called proposed by Rutherford ?
Nuclear model
