The uncertain location of electrons - George Zaidan and Charles Morton

Negotova lokacija elektronov – George Zaidan in Charles Morton

Translator: Mojca Miklavec Reviewer: Nika Kotnik

You probably know that all stuff is made up of atoms

Verjetno vam je znano, da je vsa snov sestavljena iz atomov

and that an atom

in da je atom v resnici zelo, zelo, zelo, zelo droben delec.

is a really, really, really, really tiny particle.

Every atom has a core,

Vsak atom ima jedro, sestavljeno iz vsaj enega pozitivno nabitega delca

which is made up of at least one

positively charged particle

called a proton,

po imenu proton.

and in most cases,

In v večini primerov

some number of neutral particles called neutrons.

še iz nekaj nevtralnih delcev, ki jih imenujemo nevtroni.

That core is surrounded

by negatively charged particles called electrons.

Jedro je obkroženo z negativno nabitimi delci po imenu elektroni.

The identity of an atom is determined

Identiteto atoma določa zgolj število protonov v jedru.

only by the number of protons in its nucleus.

Hydrogen is hydrogen because it has just one proton,

Vodik je vodik, ker ima zgolj en proton,

carbon is carbon because it has six,

ogljik je ogljik, ker jih ima šest,

gold is gold because it has 79,

zlato je zlato, ker jih ima 79,

and so on.

in tako dalje.

Indulge me in a momentary tangent.

Dovolite mi, da za trenutek zaidem s teme.

How do we know about atomic structure?

Kako vemo, kako so zgrajeni atomi?

We can't see protons, neutrons, or electrons.

Protonov, nevtronov in elektronov ne moremo videti.

So, we do a bunch of experiments

Zato naredimo kopico poskusov

and develop a model for what we think is there.

in razvijemo model za to, kar si predstavljamo, da je v atomu.

Then we do some more experiments

Potem naredimo še nekaj poskusov, da vidimo, če so skladni z modelom.

and see if they agree with the model.

If they do, great.

Če so, krasno.

If they don't, it might be time for a new model.

Če niso, je morda čas za nov model.

We've had lots of very different models for atoms

Imeli smo veliko različnih modelov atoma,

since Democritus in 400 BC,

od Demokrita leta 400 pr. n. št. dalje

and there will almost certainly

in skoraj gotovo bomo imeli še veliko novih.

be many more to come.

Okay, tangent over.

OK, nazaj na temo.

The cores of atoms tend to stick together,

Jedra atomov so nagnjena k temu, da se držijo skupaj,

but electrons are free to move,

toda elektroni se lahko prosto gibljejo, zato jih kemiki obožujejo.

and this is why chemists love electrons.

If we could marry them,

Če bi se lahko, bi se kar poročili z njimi.

we probably would.

But electrons are weird.

Toda elektroni so čudni.

They appear to behave either as particles,

Obnašajo se bodisi kot delci, kakor majhne žogice,

like little baseballs,

or as waves, like water waves,

ali kot valovanje, kot valovi na vodi, odvisno od eksperimenta, ki ga izvajamo.

depending on the experiment that we perform.

One of the weirdest things about electrons

Ena najbolj čudnih lastnosti elektronov je,

is that we can't exactly say where they are.

da zanje ne moremo natančno povedati, kje so.

It's not that we don't have the equipment,

Ne gre za to, da nimamo pripomočkov,

it's that this uncertainty

pač pa je ta negotovost del našega modela elektrona.

is part of our model of the electron.

So, we can't pinpoint them, fine.

Torej, ne moremo s prsti pokazati nanje, v redu.

But we can say there's a certain probability

Lahko pa povemo, da je določena verjetnost,

of finding an electron in a given space

da najdemo elektron v danem prostoru okrog jedra.

around the nucleus.

And that means that we can ask the following question:

To pomeni, da lahko zastavimo sledeče vprašanje:

If we drew a shape around the nucleus

Če bi okrog jedra narisali tako obliko,

such that we would be 95% sure

da bi lahko s 95 % gotovostjo našli dani elektron znotraj tega telesa –

of finding a given electron within that shape,

what would it look like?

kakšno bi bilo to telo?

Here are a few of these shapes.

Tu je nekaj teh oblik.

Chemists call them orbitals,

Kemiki jim pravijo orbitale in izgled vsake od njih

and what each one looks like

depends on, among other things,

je med drugim odvisen od tega, koliko energije ima.

how much energy it has.

The more energy an orbital has,

Več energije kot ima orbitala,

the farther most of its density is

bolj je večina njene gostote oddaljena od jedra.

from the nucleus.

By they way, why did we pick 95%

Mimogrede, zakaj smo si izbrali 95 % in ne 100 %?

and not 100%?

Well, that's another quirk

To je še ena posebnost našega modela elektrona.

of our model of the electron.

Past a certain distance from the nucleus,

Na določeni razdalji stran od jedra začne verjetnost nahajanja elektrona padati

the probability of finding an electron

starts to decrease

more or less exponentially,

bolj ali manj eksponentno,

which means that while it will approach zero,

kar pomeni, da čeprav se ničli približuje, je nikoli ne bo zares dosegla.

it'll never actually hit zero.

So, in every atom,

Zato je v vsakem atomu neka majhna, a neničelna verjetnost,

there is some small, but non-zero, probability

that for a very, very short period of time,

da se za zelo, zelo kratek čas

one of its electrons

eden od teh elektronov pojavi na drugem koncu znanega vesolja.

is at the other end of the known universe.

But mostly electrons stay close to their nucleus

Večinoma pa se elektroni zadržujejo blizu svojega jedra

as clouds of negative charged density

kot oblaki negativno nabite gostote, ki se sčasoma premika in preoblikuje.

that shift and move with time.

How electrons from one atom

S tem, kako elektroni enega atoma interagirajo z elektroni drugega atoma,

interact with electrons from another

determines almost everything.

je določeno skoraj vse.

Atoms can give up their electrons,

Atomi se lahko odrečejo svojim elektronom in jih predajo drugim atomom

surrendering them to other atoms,

or they can share electrons.

ali si elektrone delijo med seboj.

And the dynamics of this social network

Dinamika te socialne mreže je to, kar dela kemijo zanimivo.

are what make chemistry interesting.

From plain old rocks

Od navadnih kamnin do čudovite zapletenosti življenja,

to the beautiful complexity of life,

the nature of everything we see,

je narava vsega, kar vidimo, slišimo, okušamo, vonjamo, tipamo in celo čutimo,

hear,

smell, taste, touch, and even feel

is determined at the atomic level.

določena na nivoju atomov.