P1.1 THE PARTICLE MODEL Flashcards
(36 cards)
what is a model?
a model in science is a way of visualising or representing a scientific idea to help us understand
why might a model be updated?
when new scientific evidence cannot be explained
who developed one of the first models of an atom?
John Dalton
what information did he know about the atom?
each atom was a small indestructible sphere /all the atoms in an element are the same/the atoms in one element are different to ones in another
why is Daltons model of an atom different compared to the modern model?
because Daltons model did not include neutrons, protons and electrons or an outer shell. t
how is Daltons model of an atom similar to the modern one?
they are both a small sphere and all the elements in an atom are the same. they also know that atoms in one element are different to ones in another
what information dd J.J Thomson know about the atom?
he discovered the electron/knew it was much smaller the the atom and came up with a new model-plum pudding model/thought an atom was a positive mass/ throughout it were negative charges
why did Thomson change the model of the atom?
so it would include other parts of the model he discovered
why is Thomson’s model of the atom closer to the modern model than Daltons?
because it includes negative charges and a positive area
what’s the difference between Thomson’s model and the modern model?
in the modern model there is no positive mass but positive charges instead ad the modern model has more of a layout instead of the atoms being scattered everywhere unlike Thomson’s model
why did Thomson make the atom positive?
to cancel out the negative charges of the electrons
how big is an atom?
approximately 1x10 to the power of -10m
what is the size of an atom to normal numbers?
0.000000001m
how many atoms fit into one meter?
10000000000 atoms=1x10 to the power of 10
what is the approximate length in standard form of a molecule 10 atoms long?
10 x 1x10 to the power of -10=1x10 to the power of -9
how did Ernest Rutherford develop his model of an atom?
by scattering alpha particles from gold foil
what did think each atom consisted of?
a tiny positively charged nucleus containing the mass of an atom/most of an atom is empty space and electrons were randomly arranged
what is the nucleus size?
1x10 to the power of -15m
how did Rutherford’s model of the atom work?
most of the alpha particles passed through the atom which proves that most of the atom is empty space. some particles are deflected slightly but other particles are being repelled by the positive nucleus . this shows atoms have a small positively charged nucleus.
how is Rutherford’s model to the modern model?
because the modern model doesn’t have a whole positive nucleus unlike Rutherford’s model
through Rutherford’s findings which could have been predicted from the previously accepted “ plum pudding “ model of the atom?
the alpha particles passed straight trough undeviated
why did Rutherford’s experiment cause the “plum pudding” model to be abandoned?
because he had new information which proved the model wrong
why did most of the alpha particles pass through undeviated?
because there was empty space
why were some of the alpha particles deflected by the nucleus?
because they were both positively charged and they repel
