p2 Help - Rutherford Watch

Aty100
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Hey guys, so i really really need some help for my physics homework. I didnt go school one day and in that lesson the teacher did about 3 pages from the aqa text book on p2 chapter 6. On the last day of school he set us homework on chapter 6 and im really confused and its due first day back.

The homework is to recreate the page from Rutherford's lab book describing his experiment which disproved the plum pudding model.
Include:
a hypothesis
procedure
results
conclusion

I have no idea who Rutherford is and what the plum pudding is. Please could someone help me with this???
Thank you

+i know what his hypothesis is now so help with the others will be very appreciated
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vekril
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I'm sure it'd be more helpful to you to research yourself.
Basically, he set up a source of alpha particles aimed at a thin gold sheet and a screen to detect them inside a vaccum. The plum pudding model would suggest that all alpha particles pass through the gold sheet and hit the screen in about the same spot. However, this did not happen. Most particles passed through undeflected which shows that the atoms are mostly empty space. A few particles are deflected backwards which shows there is a small, concentrated positive charge at the centre of the atom - its nucleus.
Hope this helped, I struggled with this topic when I did my GCSEs. (:
To clarify: the plum pudding model was suggested by JJ Thomson. He said that the atom comprised of a positive 'pudding' with negative charges scattered throughout like 'plumbs'. And Rutherford disproved this with his experiment.
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Aty100
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(Original post by vekril)
I'm sure it'd be more helpful to you to research yourself.
Basically, he set up a source of alpha particles aimed at a thin gold sheet and a screen to detect them inside a vaccum. The plum pudding model would suggest that all alpha particles pass through the gold sheet and hit the screen in about the same spot. However, this did not happen. Most particles passed through undeflected which shows that the atoms are mostly empty space. A few particles are deflected backwards which shows there is a small, concentrated positive charge at the centre of the atom - its nucleus.
Hope this helped, I struggled with this topic when I did my GCSEs. (:
To clarify: the plum pudding model was suggested by JJ Thomson. He said that the atom comprised of a positive 'pudding' with negative charges scattered throughout like 'plumbs'. And Rutherford disproved this with his experiment.
Thanks that did help. Im still struggling to find a proper hypothesis to start with. I think ive found enough info to write the procedure, results and conclusion. Just need a hypothesis. Which do you think is better:

1 - atoms are permeable neutral balls expect: high energy (megavolt) charged alpha particles will zip through, lighting up small region at the back of screen

2 - atom consisted of a hard core (named the nucleus in 1912) that contained almost all the mass of the atom and had a positive charge, and that the electrons, which had little mass and a negative charge, orbited the core at a distance.

To be honest i just really need a solid hypothesis so i can start writing the rest because i understand it now. Which do you think is better? or do you have another better one?
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vekril
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I think the first one is more relavent
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Stonebridge
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Rutherford's hypothesis was that all the positive charge and nearly all the mass of the atom were concentrated in a very small volume or nucleus at the centre of the atom.
He did the maths to predict what would happen (to the beam of alpha particles) if this were the case.
His two students, Geiger and Marsden, did the experiment to test this.
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Aty100
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(Original post by Stonebridge)
Rutherford's hypothesis was that all the positive charge and nearly all the mass of the atom were concentrated in a very small volume or nucleus at the centre of the atom.
He did the maths to predict what would happen (to the beam of alpha particles) if this were the case.
His two students, Geiger and Marsden, did the experiment to test this.
thank you
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Holmstock
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(Original post by Aty100)
Thanks that did help. Im still struggling to find a proper hypothesis to start with. I think ive found enough info to write the procedure, results and conclusion. Just need a hypothesis. Which do you think is better:

1 - atoms are permeable neutral balls expect: high energy (megavolt) charged alpha particles will zip through, lighting up small region at the back of screen

2 - atom consisted of a hard core (named the nucleus in 1912) that contained almost all the mass of the atom and had a positive charge, and that the electrons, which had little mass and a negative charge, orbited the core at a distance.
To be honest i just really need a solid hypothesis so i can start writing the rest because i understand it now. Which do you think is better? or do you have another better one?
It's a long time since I read about this, but wasn't his hypothesis the plum pudding model? He was therefore expecting fairly small deflections, but was able to collect data from a wide angle. I thought that the point was that a tiny percentage bounced back, and rather than ignoring these, he then refined the experiment to get more data on these outliers, and proved that the original hypothesis could not be true....
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Aty100
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Guys in the procedure shall i just write about how he did they experiment something like an method or do i have to include other stuff as well?
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Hexaneandheels
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I thought so too, they were basically testing the Plum Pudding model and testing to see the angles of scattering by firing the alpha particles at a gold film...expecting to see flashes of light within a small angle of the beam... but most of the alpha particles passed straight through the gold film and some scattered at angles greater than 90 degrees...which brought them to the 3 new conclusions that: The nuclei must be positive, very small and most of the mass and positive charge must be contained within the nucleus.
(Original post by Holmstock)
It's a long time since I read about this, but wasn't his hypothesis the plum pudding model? He was therefore expecting fairly small deflections, but was able to collect data from a wide angle. I thought that the point was that a tiny percentage bounced back, and rather than ignoring these, he then refined the experiment to get more data on these outliers, and proved that the original hypothesis could not be true....
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Stonebridge
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OK let's just take a look here.
The question is asking about "Rutherford's Experiment". One experiment? Which one?

Now between 1909 and 1911 Rutherford (or more accurately, his two student's I mentioned before) performed a number of experiments where alpha particles were scattered by gold foil. He was looking at and testing the plumb pudding model.
Over this period he obtained results which were not consistent with that model. Namely, that a small, but significant number of alphas were deflected through angles which were too large to be accounted for by that theory.
He then suggested, in 1911, the hypothesis that the atom has a positively charged core (now called nucleus) which contains most of the mass of the nucleus and all the positive charge.
Rutherford then, on the basis of this model, calculated that the number of alphas scattered through an angle ϴ would be proportional to cosec4 (ϴ/2).
Geiger and Marsden then performed an experiment to test this hypothesis, and confirmed it in 1913.
This experiment (actually a series of experiments) is generally referred to as THE alpha particle scattering experiment, which demonstrated the existence of the nucleus and supported Rutherford's hypothesis.

The homework question I can only assume refers to this experiment and this hypothesis.
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Aty100
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(Original post by Stonebridge)
OK let's just take a look here.
The question is asking about "Rutherford's Experiment". One experiment? Which one?

Now between 1909 and 1911 Rutherford (or more accurately, his two student's I mentioned before) performed a number of experiments where alpha particles were scattered by gold foil. He was looking at and testing the plumb pudding model.
Over this period he obtained results which were not consistent with that model. Namely, that a small, but significant number of alphas were deflected through angles which were too large to be accounted for by that theory.
He then suggested, in 1911, the hypothesis that the atom has a positively charged core (now called nucleus) which contains most of the mass of the nucleus and all the positive charge.
Rutherford then, on the basis of this model, calculated that the number of alphas scattered through an angle ϴ would be proportional to cosec4 (ϴ/2).
Geiger and Marsden then performed an experiment to test this hypothesis, and confirmed it in 1913.
This experiment (actually a series of experiments) is generally referred to as THE alpha particle scattering experiment, which demonstrated the existence of the nucleus and supported Rutherford's hypothesis.

The homework question I can only assume refers to this experiment and this hypothesis.
i agree with you but to be honest the question is all i know i have no idea what experiment it is relating to but im guessing your correct
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