Dalton All Matter is Made of Indivisible and Indestructible Atoms

7/24/2019 Dalton All Matter is Made of Indivisible and Indestructible Atoms

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Daltonall matter is made of indivisible and indestructible atoms, 2) atoms of

a given element are identical in their physical and chemical properties, 3)

atoms of dierent elements have dierent physical and chemical properties,

4) atoms of dierent elements combine in simple whole-number ratios to

form chemical compounds, 5) atoms cannot be subdivided, created or

destroyed when they are combined, separated, or rearranged in chemical

reactions!ne wea"ness was that the atom was found to be indivisible, and

they had smaller particles

#homson

$toms were made from a positively charged substance with negatively

charged electrons scattered about, li"e raisins in a pudding

#he model was incorrect for many reasons

#he primary reason is because there is no cloud of positive charge

#here are protons instead with a nucleus

$nd also neutrons

cod % is the best and godli"e

rutherford

materi Rutherford's Theory was that atom is mostly empty space, thus explaining the lack of

deflection of most of the alpha particles, when he tested out the Gold-Foil Experiment.Rutherford predicted that all the alpha particles would go through the gold foil, howeer,

when tested, some of the alpha particles reflected !ack, !ounced off the gold foil at ery large

angles.

strengths"

#$ -electrons moe fast through the atom.


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%$ -electrons are trapped within the atom !y a positiely charged nucleus

&$ -electrons are negatiely charged.

$ weaknesses"

($ -failed to discoer the nucleus contains positiely charged particles called protons

)$ -failed to discoer the nucleus also contains neutrons *a su! atomic neutral particle$

electrons move in de&nite orbits around the nucleus, much li"e planets circle the

sun #hese orbits, or energy levels, are located at certain distances from thenucleus

wea"nesss') the path of electron around nucleus is considered to be circular of

de&nite radius but in reality it can be at any distance from the nucleus 2) the

model is based on spectra of atoms and newton(s laws of motion which are not

applicable to microscopic particles

b) heisenberg(s principle is it is not possible to determine simultaneously the

position and the speed of a moving microscopic particle in space

c)de broglie suggested the idea of matter waves by arguing that if radiation canbe regarded to have dual nature then a moving ob*ect thought to be a particle

should also show wave nature

4a) orbit- the path in which the electron revolves around the nucleus is caleed

an orbit

orbital- the spatial area around the nucleus in which the probability of &nding an

electron is ma+imum is an orbital

b) principal uantum number

hat experiment did Niels Bohr do.

he performed e+periments on the hydrogen spectrum

Colour blindness
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This image shows a num!er or +, !ut someone who is deuteranopicmay not !e a!le to

see it.

n #+, shortly after his arrial in anchester, /alton was elected a mem!er of the

anchester 0iterary and 1hilosophical 2ociety,the 30it 4 1hil3, and a few weeks later hecommunicated his first paper on 3Extraordinary facts relating to the isionof colours3, in

which he postulated that shortage in colour perception was caused !y discolouration of the

li5uid medium of the eye!all. n fact, a shortage of colour perception in some people had not

een !een formally descri!ed or officially noticed until /alton wrote a!out his own.

6lthough /alton's theory lost credence in his own lifetime, the thorough and methodical

nature of his research into his own isual pro!lem was so !roadly recogni7ed that /altonism

!ecame a common term for color !lindness. Examination of his presered eye!all in #++(

demonstrated that /alton actually had a less common kind of colour !lindness,

deuteroanopia, in which medium waelength sensitie cones are missing *rather than

functioning with a mutated form of their pigment, as in the most common type of colour

!lindness, deuteroanomaly$. 8esides the!lueandpurpleof the spectrumhe was a!le torecogni7e only one colour,yellow, or, as he says in his paper,

that part of the image which others call redappears to me little more than a shade or defect

of light. After that theorange, yellow andgreenseem one colour which descends pretty

uniformly from an intense to a rare yellow, making what I should call different shades of

yellow

This paper was followed !y many others on dierse topics onrainanddewand the origin of

springs, on heat, the colour of the sky,steam,the auxiliary er!sandparticiplesof the

English languageand the reflectionand refractionof light.

[edit] Atomic theory

n #9::, /alton !ecame a secretary of the anchester 0iterary and 1hilosophical 2ociety,

and in the following year he orally presented an important series of papers, entitled

3Experimental Essays3 on the constitution of mixed gases; on thepressureof steam and other

apoursat different temperatures, !oth in a acuumand in air; on eaporation; and on the

thermal expansionof gases. These four essays were pu!lished in theMemoirsof the 0it 4

1hil in #9:%.

The second of these essays opens with the striking remark,
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There can scarcely be a doubt entertained respecting the reducibility of all elastic fluids of

whatever kind, into liquids; and we ought not to despair of affecting it inlow temperatures

and by strong pressures eerted upon the unmied gases further.

6fter descri!ing experiments to ascertain the pressure of steam at arious points !etween :

and #:: ac5ues 6lexandre =?sar =harles, #9%:
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@e thus enunciated Gay-0ussac's lawor >.6.=. =harles's law, pu!lished in #9:% !y>oseph

0ouis Gay-0ussac. n the two or three years following the reading of these essays, /alton

pu!lished seeral papers on similar topics, that on the a!sorption of gases !y water and other

li5uids *#9:&$, containing his law of partial pressures now known as /alton's law.

The most important of all /alton's inestigations are those concerned with the atomic theoryin chemistry, with which his name is insepara!ly associated. t has !een proposed that this

theory was suggested to him either !y researches on ethylene*olefiant gas$ and methane

*carburetted hydrogen$ or !y analysis of nitrous oxide*protoide of a!ote$ andnitrogen

dioxide*deutoide of a!ote$, !oth iews resting on the authority of Thomas Thomson.

@oweer, a study of /alton's own la!oratory note!ooks, discoered in the rooms of the 0it 4

1hil,A&Bconcluded that so far from /alton !eing led !y his search for an explanation of the law

of multiple proportionsto the idea that chemical com!ination consists in the interaction of

atoms of definite and characteristic weight, the idea of atoms arose in his mind as a purely

physical concept, forced upon him !y study of the physical properties of the atmosphereand

other gases. The first pu!lished indications of this idea are to !e found at the end of his paper

on the a!sorption of gases already mentioned, which was read on %# Ccto!er #9:&, thoughnot pu!lished until #9:(. @ere he says"

"hy does not water admit its bulk of every kind of gas alike# This question I have duly

considered, and though I am not able to satisfy myself completely I am nearly persuaded that

the circumstance depends on the weight and number of the ultimate particles of the several

gases.

[edit] Atomic weights

/alton proceeded to print his first pu!lished ta!le of relatie atomic weights.2ix elementsappear in this ta!le, namely hydrogen, oxygen, nitrogen, car!on, sulfur, and phosphorus, with

the atom of hydrogen conentionally assumed to weigh #. /alton proided no indication in

this first paper how he had arried at these num!ers. @oweer, in his la!oratory note!ook

under the date ) 2eptem!er #9:&ABthere appears a list in which he sets out the relatie

weights of the atoms of a num!er of elements, deried from analysis of water, ammonia,

car!on dioxide, etc. !y chemists of the time.

t appears, then, that confronted with the pro!lem of calculating the relatie diameter of the

atoms of which, he was coninced, all gases were made, he used the results of chemical

analysis. 6ssisted !y the assumption that com!ination always takes place in the simplest

possi!le way, he thus arried at the idea that chemical com!ination takes place !etweenparticles of different weights, and it was this which differentiated his theory from the historic

speculations of the Greeks, such as /emocritusand 0ucretius.Acitation neededB

The extension of this idea to su!stances in general necessarily led him to the law of multiple

proportions, and the comparison with experiment !rilliantly confirmed his deduction.A(Bt

may !e noted that in a paper on the proportion of the gases or elastic fluids constituting the

atmosphere, read !y him in Doem!er #9:%, the law of multiple proportions appears to !e

anticipated in the words" 3The elements of oxygen may com!ine with a certain portion of

nitrous gas or with twice that portion, !ut with no intermediate 5uantity3, !ut there is reason

to suspect that this sentence may hae !een added some time after the reading of the paper,

which was not pu!lished until #9:(.
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=ompounds were listed as !inary, ternary, 5uaternary, etc. *molecules composed of two,

three, four, etc. atoms$ in the$ew %ystem of &hemical 'hilosophydepending on the num!er

of atoms a compound had in its simplest, empirical form.

@e hypothesi7ed the structure of compounds can !e represented in whole num!er ratios. 2o,

one atom of element com!ining with one atom of element is a !inary compound.Furthermore, one atom of element com!ining with two elements of or ice ersa, is a

ternary compound. any of the first compounds listed in the$ew %ystem of &hemical

'hilosophycorrespond to modern iews, although many others do not.

arious atoms and moleculesas depicted in >ohn /alton'sA $ew %ystem of &hemical

'hilosophy*#9:9$.

/alton used his own sym!ols to isually represent the atomic structure of compounds. These

hae made it in$ew %ystem of &hemical 'hilosophywhere /alton listed a num!er of

elements, and common compounds.

[edit] Five main points of Dalton's atomic theory

#. The atoms of a gien element are different from those of any other element; the atoms

of different elements can !e distinguished from one another !y their respectie

relatie atomic weights.

%. 6ll atoms of a gien elementare identical.

&. 6toms of one element can com!ine with atoms of other elements to form chemical

compounds; a gien compound always has the same relatie num!ers of types of

atoms.
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. 6toms cannot !e created, diided into smaller particles, nor destroyed in the chemical

process; a chemical reactionsimply changes the way atoms are grouped together.

(. Elements are made of tiny particles called atoms.

/alton proposed an additional 3rule of greatest simplicity3 that created controersy, since itcould not !e independently confirmed.

Hhen atoms com!ine in only one ratio, 3..it must !e presumed to !e a !inary one,

unless some cause appear to the contrary3.

This was merely an assumption, deried from faith in the simplicity of nature. Do eidence

was then aaila!le to scientists to deduce how many atoms of each element com!ine to form

compound molecules. 8ut this or some other such rule was a!solutely necessary to any

incipient theory, since one needed an assumed molecular formula in order to calculate relatie

atomic weights. n any case, /alton's 3rule of greatest simplicity3 caused him to assume that

the formula for water was C@ and ammonia was D@, 5uite different from our modernunderstanding.

/espite the uncertainty at the heart of /alton's atomic theory, the principles of the theory

suried. To !e sure, the coniction that atoms cannot !e su!diided, created, or destroyed

into smaller particles when they are com!ined, separated, or rearranged in chemical reactions

is inconsistent with the existence of nuclear fusionandnuclear fission, !ut such processes are

nuclear reactions and not chemical reactions. n addition, the idea that all atoms of a gien

element are identical in their physical and chemical properties is not precisely true, as we

now know that differentisotopesof an element hae slightly arying weights. @oweer,

/alton had created a theory of immense power and importance. ndeed, /alton's innoation

was fully as important for the future of the science as 6ntoine 0aurent 0aoisier's oxygen-

!ased chemistry had !een.

[edit] Later years

>ames 1rescott >oule

/alton communicated his atomic theory to Thomson who, !y consent, included an outline of

it in the third edition of his %ystem of &hemistry*#9:$, and /alton gae a further account of
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it in the first part of the first olume of his$ew %ystem of &hemical 'hilosophy*#9:9$. The

second part of this olume appeared in #9#:, !ut the first part of the second olume was not

issued till #9%. This delay is not explained !y any excess of care in preparation, for much of

the matter was out of date and the appendix giing the author's latest iews is the only portion

of special interest. The second part of ol. ii. neer appeared.

@e was president of the(it ) 'hilfrom #9# until his death, contri!uting ##) memoirs. Cf

these the earlier are the most important. n one of them, read in #9#, he explains the

principles of olumetric analysis, in which he was one of the earliest workers. n #9: a

paper on thephosphatesand arsenates, often regarded as a weaker work, was refused !y the

Royal 2ociety, and he was so incensed that he pu!lished it himself. @e took the same course

soon afterwards with four other papers, two of which **n the quantity of acids,basesand

saltsin different varieties of saltsand *n a new and easy method of analysingsugar$ contain

his discoery, regarded !y him as second in importance only to the atomic theory, that certain

anhydrates, when dissoled in water, cause no increase in its olume, his inference !eing that

the salt enters into theporesof the water.

>ames 1rescott >oulewas a famous pupil of /alton.

[edit] Dalton's eperimental method

2ir @umphry /ay, #9&: engraing !ased on the painting !y 2ir Thomas 0awrence *#)+-

#9&:$

6s an inestigator, /alton was often content with rough and inaccurateinstruments, though

!etter ones were o!taina!le. 2ir@umphry /aydescri!ed him as 3a ery coarseexperimenter3, who almost always found the results he re5uired, trusting to his head rather

than his hands. Cn the other hand, historians who hae replicated some of his crucial

experiments hae confirmed /alton's skill and precision.

n the preface to the second part of olume of his$ew %ystem, he says he had so often !een

misled !y taking for granted the results of others that he determined to write 3as little as

possi!le !ut what can attest !y my own experience3, !ut this independence he carried so far

that it sometimes resem!led lack of receptiity. Thus he distrusted, and pro!a!ly neer fully

accepted, Gay-0ussac's conclusions as to the com!ining olumes of gases. @e held

unconentional iews on chlorine.Een after its elementary character had !een settled !y

/ay, he persisted in using the atomic weights he himself had adopted, een when they had!een superseded !y the more accurate determinations of other chemists. @e always o!Iected
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to the chemical notation deised !y >Jns >ako! 8er7elius, although most thought that it was

much simpler and more conenient than his own cum!ersome system of circular sym!ols.

[edit] !ublic and personal life

>ohn /alton *fromArthur %huster ) Arthur +. %hipley8ritain's @eritage of 2cience.

(ondon, --/$

8efore he had propounded the atomic theory, he had already attained a considera!le scientific

reputation. n #9:, he was chosen to gie a course of lectures on natural philosophy at theRoyal nstitutionin 0ondon, where he deliered another course in #9:+K#9#:. @oweer,

some witnesses reported that he was deficient in the 5ualities that make an attractie lecturer,

!eing harsh and indistinct in oice, ineffectie in the treatment of his su!Iect, and singularly

wanting in the language and power of illustration.

n #9#:, 2ir @umphry /ay asked him to offer himself as a candidate for the fellowship of

the Royal 2ociety,!ut /alton declined, possi!ly for financial reasons. @oweer, in #9%% he

was proposed without his knowledge, and on election paid the usual fee. 2ix years preiously

he had !een made a corresponding mem!er of the French6cad?mie des 2ciences,and in

#9&: he was elected as one of its eight foreign associates in place of /ay.

n #9&&, Earl Grey's goernment conferred on him a pension ofL#(:, raised in #9&) to L&::.

/alton neer married and had only a few close friends. @e lied for more than a 5uarter of a

century with his friend the Re. H. >ohns *##K#9($, in George 2treet, anchester, where

his daily round of la!oratory work and tuition was !roken only !y annual excursions to the

0ake /istrictand occasional isits to 0ondon. n #9%% he paid a short isit to 1aris,where he

met many distinguished resident scientists. @e attended seeral of the earlier meetings of the

8ritish 6ssociationat ork, Cxford,/u!linand 8ristol.

[edit] Death and legacy
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8ust of /alton !y =hantrey

/alton suffered a minor strokein #9&, and a second one in #9&9 left him with a speech

impediment, though he remained a!le to do experiments. n ay #9 he had yet another

stroke; on %) >uly he recorded with trem!ling hand his last meteorological o!seration. Cn

% >uly, in anchester, /alton fell from his !ed and was found lifeless !y his attendant.

@e was !uried in anchester in 6rdwick cemetery. The cemetery is now a playing field, !ut

pictures of the original grae are in pu!lished materials.A)BAB

6 !ust of /alton, !y =hantrey, was pu!licly su!scri!ed forA9Band placed in the entrance hall

of the Royal anchester nstitution. =hantrey also crafted a large statue of /alton, now in the

anchester Town @all.

n honour of /alton's work, many chemists and !iochemists use the *as yet unofficial$ unit

dalton*a!!reiated /a$ to denote one atomic mass unit, or #M#% the weight of a neutral atom

of car!on-#%. There is a >ohn /alton 2treet connecting /eansgateand 6l!ert 25uarein the

centre of anchester.

anchester etropolitan Nniersityhas a !uilding named after >ohn /alton and occupied !y

the Faculty of Technology, in which the maIority of its 2cience 4 Engineering lectures and

classes take place. 6 statue is outside the >ohn /alton 8uilding of the anchester

etropolitan Nniersity in =hester 2treet which has !een moed from 1iccadilly. t was the

work of Hilliam Theed *after =hantrey$ and is dated #9(( *it was in 1iccadilly until #+))$.

The Nniersity of anchesterhad a hall of residence called /alton @all;it also esta!lished

two /alton =hemical 2cholarships, two /alton athematical 2cholarships, and a /alton

1ri7e for Datural @istory. There is also a /alton edal awarded occasionally !y the

anchester 0iterary and 1hilosophical 2ociety*only #% times altogether$.

6lunar craterhas !een named after /alton. 3/altonism3 !ecame a common term for colour

!lindness and 3/altonien3 is the actual French word for 3colour !lind3.

The name /alton can often !e heard in the halls of many Ouaker schools, for example, one of

the school houses in =oram @ouse, the primary sector of 6ckworth 2chool, is called /alton.
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11/15

uch of his collected work was damaged during the !om!ing of the anchester 0iterary and

1hilosophical 2ociety on % /ecem!er #+:. This eent prompted saac 6simoto say, 3>ohn

/alton's records, carefully presered for a century, were destroyed during theHorld Har

!om!ing of anchester. t is not only the liing who are killed in war.3 The damaged papers

are now in the >ohn Rylands 0i!raryhaing !een deposited in the uniersity li!rary !y the

society.

J. J. THOMSONS CATHODE RAY EXER!MENT/ / #homson was one of the great scientists of the '0th century1 his inspired and

innovative cathode ray e+periment greatly contributed to our understanding of

the modern world

by artyn huttleworth26)

0ike most scientists of that era, he inspired generations of later physicists, from Einstein to

@awking.

@is !etter-known research proed the existence of negatiely charged particles, later calledelectrons, and earned him a desered Do!el 1ri7e for physics. This research led to further

experiments !y 8ohr and Rutherford, leading to an understanding of the structure of the

atom.

7$# 8 $ 9$#7!D: ;$< #=>:

:ven without consciously reali?ing it, most of us are already aware of what a

cathode ray tubeis

0ook at any glowing neon sign or any Pold-fashionedQ teleision set, and you are looking at

the modern descendants of the cathode ray tu!e.

1hysicists in the #+th century found out that if they constructed a glass tu!e with wires

inserted in !oth ends, and pumped out as much of the air as they could, an electric charge

passed across the tu!e from the wires would create a fluorescent glow. This cathode ray also

!ecame known as an Pelectron gunQ.

0ater and improed cathode ray experimentsfound that certain types of glass produced a

fluorescent glow at the positie end of the tu!e. Hilliam =rookes discoered that a tu!e

coated in a fluorescing material at the positie end, would produce a focused PdotQ when raysfrom the electron gun hit it.
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12/15

Hith more experimentation, researchers found that the Pcathode raysQ emitted from the

cathode could not moe around solid o!Iects and so traeled in straight lines, a property of

waes. @oweer, other researchers, nota!ly =rookes, argued that the focused nature of the

!eam meant that they had to !e particles.

1hysicists knew that the ray carried a negatie charge !ut were not sure whether the charge

could !e separated from the ray. They de!ated whether the rays were waes or particles, as

they seemed to exhi!it some of the properties of !oth. n response, >. >. Thomson constructed

some elegant experiments to find a definitie and comprehensie answer a!out the nature of

cathode rays.

#7!!@A B8;# 9$#7!D: ;$< :C:;8:@#

#homson had an in"ling that the EraysA emitted from the electron gun were

inseparable from the latent charge, and decided to try and prove this by using a

magnetic &eld

@is first experiment was to !uild a cathode ray tu!e with a metal cylinder on the end. This

cylinder had two slits in it, leading to electrometers, which could measure small electric

charges.

@e found that !y applying a magnetic field across the tu!e, there was no actiity recorded !y

the electrometers and so the charge had !een !ent away !y the magnet. This proed that the

negatie charge and the ray were insepara!le and intertwined.

#7!!@A 9$#7!D: ;$< :9!@D :C:;8:@#

Fi"e all great scientists, he did not stop there, and developed the second stage of

the e+periment, to prove that the rays carried a negative charge #o prove this

hypothesis, he attempted to deGect them with an electric &eld

Earlier experiments had failed to !ack this up, !ut Thomson thought that the acuum in the

tu!e was not good enough, and found ways to improe greatly the 5uality.

For this, he constructed a slightly different cathode ray tu!e, with a fluorescent coating at one

end and a near perfect acuum. @alfway down the tu!e were two electric plates, producing apositie anode and a negatie cathode, which he hoped would deflect the rays.

6s he expected, the rays were deflected !y the electric charge, proing !eyond dou!t that the

rays were made up of charged particles carrying a negatie charge. This result was a maIor

discoery in itself, !ut Thomson resoled to understand more a!out the nature of these

particles.

#7!!@A #78;D :C:;8:@#

#he third e+periment was a brilliant piece of scienti&c deductionand shows howa series of e+periments can gradually uncover truths
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13/15

any great scientificdiscoeries inole performing a series of interconnected experiments,

gradually accumulating data and proing a hypothesis.

@e decided to try to work out the nature of the particles. They were too small to hae their

mass or charge calculated directly, !ut he attempted to deduce this from how much the

particles were !ent !y electrical currents, of arying strengths.

Thomson found out that the mass to charge ratio was so high that the particles either carried a

huge charge, or were a thousand time smaller than a hydrogen ion. @e decided upon the latter

and came up with the idea that the cathode rays were made of particles that emanated from

with the atoms themseles, a ery !old and innoatie idea.

F$#:; D:H:F!:@#

#homson came up with the initial idea for the structure of the atom, postulating

that it consisted of these negatively charged particles swimming in a sea of

positive charge 7is pupil, ;utherford, developed the idea and came up with the

theory that the atom consisted of a positively charged nucleus surrounded by

orbiting tiny negative particles, which he called electrons

Ouantum physics has shown things to !e a little more complex than this !ut all 5uantum

physicists owes their legacy to Thomson. 6lthough atoms were known a!out, as apparently

indiisi!le elementary particles, he was the first to postulate that they had a complicated

internal structure.

ThomsonQs greatest gift to physics was not his experiments, !ut the next generation of great

scientists who studied under him, including Rutherford, Cppenheimer and 6ston. These great

minds were inspired !y him, marking him out as one of the grandfathers of modern physics.

;ead moreI httpIJJwwwe+periment-resourcescomJcathode-

rayhtmlKi+??v7HiBap

The Rutherford Experiment

6t the turn of the century, there was little known a!out atoms except that they contained

electrons. >. >. Thompson discoered the electron in #9+, and there was considera!le

speculation a!out where these negatiely charged particles existed in nature. atter is

electrically neutral; some positie charge must !alance the charge of the electron. Cne

popular theory of the time was called the Pplum pudding modelQ. This model, inented !y

Thompson, enisioned matter made of atoms that were spheres of positie charge spiked with
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14/15

electrons throughout. Electrons were chunks of plum distri!uted through a positiely charged

sphere of pudding.

n #+##, Ernest Rutherford performed an experiment to test the plum pudding model. @e

fired energetic A@e%B particles at a foil, and measured the deflection of the particles as they

came out the other side. From this he could deduce information a!out the structure of the foil.

To understand how this works, imagine shooting a rifle at a mound of loose snow" one

expects some !ullets to emerge from the opposite side with a slight deflection and a !it of

energy loss depending on how regularly the pile is packed. Cne can deduce something a!out

the internal structure of the mound if we know the difference !etween the initial *!efore it

hits the pile$ and final *after it emerges from the pile$ traIectories of the !ullet. f the mound

were made of loose, powdery snow, the !ullets would !e deflected ery little; if the !ullets

were deflected wildly, we might guess that there was a !rick of hard material inside.

Rutherford expected all of the particles to !e deflected Iust a !it as they passed through the

plum pudding. @e found that most of the Qs he shot at the foil were not deflected at all. They

passed through the foil and emerged undistur!ed. Cccasionally, howeer, particles were

scattered at huge angles. Hhile most of the Qs were undistur!ed, a few of them !ounced

!ack directly. magine if something like this happened at our mound of snow. He shoot

!ullets at the pile for days, and eery round passes straight through, unpertur!ed K then a

!ullet hits the snow, reflects !ack, and splinters the gunQs stockS RutherfordQs result lead him

to !eliee that most of the foil was made of empty space, !ut had extremely small, dense

lumps of matter inside. Do other model accounted for the occasional wide angle scattering of

the . Hith this experiment, Rutherford discoered the nucleus.

1hysicists hae since used particle scattering in many ways to learn a!out matter, and hae

had much success in studying solids. To understand some of the ways that ions are used to

pro!e solids, we consider an important techni5ue used in crystallography" Rutherford

8ackscattering"

"h#t experiment did Niels Bohr do$!n%@iels >ohrL:dit categoriesM

L8mproveM

he performed experiments on the hydrogen spectrum

"h#t &ere the experiments th#t Niels Bohr '#rried o(t to 're#te!n%@iels >ohrL:dit categoriesM

L8mproveM
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15/15

8ohr studied the spectrums of arious atoms and generali7ed his 5uantum theory from his

discoeries. @e concluded that the electrons of an atom determined many of its

characteristics.

"h#t did Niels Bohr h#*e to do &ith #n #tom$!n%@iels >ohrL:dit categoriesM

L8mproveM

>ased on conversations with ;utherford @iels >orh developed the >ohr nuclear

model of the $tom 8t is the one you have met in elementary school where

rotons and @eutrons form a core with electrons circling in &+ed orbits around

the core #he orbits e+plained some "ind of) radiation which had hitherto been a

mystery

"h#t did Niels Bohr h#*e to do &ith #n #tom$!n%@iels >ohrL:dit categoriesM

L8mproveM

>ased on conversations with ;utherford @iels >orh developed the >ohr nuclear

model of the $tom 8t is the one you have met in elementary school where

rotons and @eutrons form a core with electrons circling in &+ed orbits around

the core #he orbits e+plained some "ind of) radiation which had hitherto been a

mystery
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Documents

Dalton All Matter is Made of Indivisible and Indestructible Atoms