atomiuscaninius

the reporter with anose for sciencenews

BB Y RACHEL, COLIN, AND LUCY

it's all for science! i'mrisking my life to take thistime machine back to the

beginning of atomic theory.

after muchresearch, i

can share thesecret of

wheretheoriesabout theatom came

from.

my theoryabout atoms.

now to ace reporter, atomiuscaninius. what do you have for

us, AC?

hello, democritus.thanks for

meeting with me.

here i am in 460 BCE greece.the concept of the atom was

introduced by philosopher,democritus.

call medemmy! as i

was saying tosocrates theother night, ilove to talkabout atoms!

can you expandon your ideas?

what arethese atoms

like?

well, atoms in solids aresmall and pointed, andliquid atoms are large

and round.

hmmm. whatobservationsdid you do tocome up withyour theory? observations?

who am i?aristotle? oh,

wait, hehasn't beenborn yet. i

just thoughtabout it. it'sonly logical.

you're verywelcome.andremember tostay cheerful.it's the secret

to a long,happy life.

how did demmy's theories holdup over time? of course,scientists may make a

discovery tomorrow thatchanges everything!

to sum up. I'll give demmy's theorya b+. it's amazing that he got somuch right, but since he didn't have

any evidence, ithink he was justlucky! back to you, tiffany.

hanks for theinsightfulreport, ac.

what's next inthis series?

thank you forspeaking toour viewersabout the

atom.

I'M HEADED TO LONDON IN1803, AN EXCITING TIME AND

PLACE FOR SCIENTIFICDISCOVERIES,

WHEW! I MADE IT SAFEAND SOUND! WE'RE

MEETING JOHN DALTON, ACHEMIST WHO DEVELOPED

HIS OWN THEORY OFATOMIC STRUCTURE.

SORRY TOBOTHER YOU, DR.DALTON. WHATCAUSED YOURINTEREST INATOMS?

WHAT DID THATTELL YOU ABOUT

ATOMS?

THAT ATOMS OF DIFFERENTGASES MUST BE

DIFFERENT SIZES. I DEDUCEDTHAT ATOMS COMBINE AND

SEPARATE FROM EACHOTHER IN CHEMICAL

REACTIONS.

INTERESTING.SO YOUR IDEASCAME FROM

OBSERVING GASATOMS?

OH NO! NOBODY CAN SEEAN ATOM. THEY'RE TOO

SMALL! I MADE INFERENCESABOUT ATOMS FROM MY

MEASUREMENTS OF GASESAND MIXTURES.

I'M INTERESTED INFRANKLIN AND

ELECTRICITY, BUTWITHOUT LAVOISIER'S

WORK ONMEASURING THECOMPOSITION OFCOMPOUNDS, ICOULDN'T HAVEDEVELOPED MY

THEORY.

AS A METEOROLOGIST,I WONDERED HOW

WATER VAPOR AND AIRSHARED SPACE. I

EXPERIMENTED WITHMEASURING MIXTURESOF GASES AND THEIR

PROPERTIES.

I SEE. WHO ISYOUR

GREATESTSCIENTIFIC

INFLUENCE?

let's reviewdalton'stheory inlight ofcurrentscientificknowledge.

so, what grade should wegive dalton? let's give himan A because he based hisideas on experiments. He did

great considering hecouldn't see what he was

studying!

that is just fascinating, AC. Ican't wait for the final

installment of your exposé onthe structure of the atom.

now we're going to hear from ernestrutherford, a scientist born in newzealand, who worked in canada and

england. He made his discovery aboutthe atom in 1899. This time our

scientist is the time traveler. goodluck, ernie!

what a great opportunity tovisit the 21st century! willthere be robots? will i beable to watch plays andlisten to music in my own

home?

thank you forjoining us. ihope your

journey wascomfortable.

just fine, thankyou. i'm veryexcited to

share my ideaswith your

scientists andlearn what theyhave discovered.

i understand youare speaking to

the nationalassociation ofscientists thisafternoon. whatelse will you dowhile you are

here?

as you cansee,

Thomson'sview of the

atom,the plumpudding model,

was apositively

charged soupwith negativecorpuscles,now calledelectrons.

i had a problem. iwanted to base myideas on evidence,

but i couldn'tobserve atomsdirectly. could idraw conclusionsfrom their traces,though, i wondered.

i shot alpha particles throughgold foil and saw that most

particles passed straight through,but a few deflected at sharp

angles.

i'll visitlaboratories.i understand i

won'tremember myexperienceshere, but i'llenjoy themwhile i can!

thank you for inviting me here todayto discuss atoms. i'm also eager tolearn about those devices you call

smartphones!

i concludedthat atomsare mostlyspace and

most of theirmass is in apositivelychargednucleus

surrounded byelectrons.

did you haveany help from

otherscientists onthis project?

are there anyquestions?

yes, of course. hansgeiger and ernest

marsden conducted theexperiment in mylaboratory in

manchester, and i builtmy ideas on thomson's

theory.

well, our timetogether isover. thankyou for the

visit, and goodluck on yourreturn trip!

it's been apleasure and

anenlighteningexperience!

thank you forthe

opportunity.

this concludes my report onthe history of theories on

atomic structure. nextweek, an investigative

report on why helium makesyou talk funny!

rutherford gets an a+! hisexperiment was ingenious, andhis conclusions were mostly

correct.

so how doesrotherford's

theorymeasure up?