Model of the Atom Flashcards
to learn duh (10 cards)
What were atoms first thought to be?
Tiny spheres that could not be divided
Who created the idea of the plum pudding model and what did he discover?
JJ Thomson
Electrons
What was the plum pudding model?
The plum pudding model was a positive sphere with negatively charged electrons studded into it
What was the gold foil experiment?
An experiment that scattered alpha particles towards gold foil, detectors were used to see what happened to the alpha particles
What did the gold foil experiment prove?
Most of the alpha particles passed through the gold atoms, this is because most of the atom is empty.
Some of the particles were deflected (pushed to the side) by the positively charged nucleus.
A small number of particles bounced back because they hit the nucleus.
Who did the gold foil experiment?
Ernest Rutherford
Along with his two students Geiger and Marsden
Why was the plum pudding model replaced?
Because the gold foil experiment discovered that the mass of an atom was concentrated at its centre.
What did Niels Bohr discover?
Niels Bohr used maths to discover that electrons were found in shells at specific distances from the nucleus.
How were protons discovered?
By later experiments led to the idea that the positive charge in the nucleus could be subdivided into a number of smaller particles, each particle having the same amount of positive charge. These were called protons.
What did James Chadwick discover?
James Chadwick discovered that a particle in the nucleus were neutrons.
