The History Of The Atom Flashcards
What can new experimental evidence lead to
Scientific model being changed or replaced
What were atoms thought to be before the discovery of the electron
Tiny spheres that could not be divided
Who came up with the theory of the ‘plum pudding model’
The discovery of the electron led to JJ Thompson concluding from his experiments that atoms weren’t solid spheres, and that an atom is a ball of positive charge with negative electrons embedded in it
Who conducted the alpha particle scattering experiments
1909, Rutherford and his students Marsden
What was the alpha particle scattering experiment
They fired positively charged alpha particles at an extremely thin sheet of gold
What did the alpha particle model suggest
The mass of an atom was concentrated at the centre and that the nucleus was positively charged, a cloud of negative electrons surrounds this
Who adapted the nuclear model by suggesting that electrons orbit the nucleus at specific distances
Bohr suggested that electrons were in shells
His atomic structure was supported by many experiments
What did experiments lead to after Bohr’s nuclear model
That the nucleus could be divided into smaller particles, each particle having the same amount of positive charge, the name proton was given
When and what did the experimental work of James Chadwick provide
20 years after scientists accepted that atoms have a nuclei, James Chadwick carried out an experiment which provided evidence for neutral particles in the nucleus which are now called neutrons
