Question

An electron orbital cloud extends to infinity .
Does this mean at a specific time ;the electron is everywhere or anywhere?

Answer 1

This contradiction arise because we tend to think either purely wave or purely particle nature of electron at a time. For the former it seems like it is everywhere & for the later it seems is anywhere.

An ideal particle is completely localized & an ideal wave is completely delocalized (means everywhere). Our quantum concepts mixes these two & hence a particle is approximately but not completely localized.

It means a particular electron at a particular time is neither anywhere nor everywhere it is simply somewhere in a region not exactly at a particular point; the probability of which is maximum where the electron cloud density is maximum in the electron orbital cloud diagram.

Nevertheless we know that electron cloud orbital digram is drawn purely on the basis of probability of finding electron around the nucleus & it it extends to infinity because there is nothing like a physical boundary surrounding the electron in a particular region of space that comes because of wave nature of electron. But since the probability reduces to zero beyond a certain distance we can simply ignore them & talk about probabilities in the atomic & subatomic range of distance.

This was a great thought provoking question. It would be pleasure for me if this discussion goes further.

Answer 2

consider the Heisenberg relation for the commutator of Energy and time
\[{\Delta E \Delta T}\geq\frac{\hbar}{2}\]
at a specific, time delta T is zero . the energy of the electron is ...

Answer 3

This relation gives us the uncertainty relationship between time & energy which means it is impossible to determine both time & energy simultaneously.

When you say delta t is zero it means you are sure about the time but the delta e the uncertainty in measuring the energy will be approaching to infinite.

So whatever you speak about the energy it doesn't make any sense because there is a large error associated with it.

Answer 4

ok if we take the limit as we approach delta t approaches zero, the energy and hence the quantum number n (the shell) approach infinity hence the boundlessness of the orbital

Answer 5

yeah exactly i think so. An awesome explanation:)

Answer 6

does the uncertainty relation say we cant determine the two variables simultaneously, or does it say that the variables re not defined with such certainty

Answer 7

The uncertainty relation isn't related to our limitation of not able to find out the energy & time or momentum & position with unlimited precision rather it simply says it doesn't exist hence even the God plays dice with the universe.

So i agree with the later one in your reply.

Answer 8

so is the particle anywhere or everywhere, ?

Answer 9

Everywhere.

Answer 10

But that condradicts because it is possible only if are considering only the wave nature of electron.
Only wave can extend everywhere at a given time.

Answer 11

your right it isn't a particle

Answer 12

yes it is because we have proved it experimentally that electron shows both the nature.

Answer 13

& why electron? Everything in this universe is a particle as well as wave.

Answer 14

Let's think about a chemical reaction. If we consider wave nature of electron how would we able to explain it?

Answer 15

That is better
P and W
not
P or W,

An electron is a great size because it is near the cross over point

Answer 16

like a free radical

Answer 17

i didn't get it. Can you explain it a little bit more What is P,W?

Answer 18

particle , wave

Answer 19

oh i got

Answer 20

& cross over point?

Answer 21

i was just shortening them to emphasize the non Boolean-ness of reality.
Thing are
True and False
as apposed to
True or false

Answer 22

When i said the cross over point i was talking about how a wave and how a particle are measured

Answer 23

So what is the conclusion according to you? It is everwhere..?

Answer 24

Well it is And it isn't

Answer 25

yeah i am also saying that. When we do an experiment we can only view only aspect at one time. Either wave or either particle but not both of them.
But since we not doing an experiment we are just guessing about the position at a particular time we should consider both of them.
What do you say?

Answer 26

I would say that The particle IS both , but we can only measure one aspect Or the other,
like a coin, it is both heads and tail , but we can only see one side at a time

Answer 27

Yeah that is great. Ever since i have read the uncertainty principle it has changed my entire thinking level & i am greatly fascinated to it.

I've a doubt regarding it suppose we are compressing a gas in container & it's temperature begins to rise. is that according to uncertainty principle?
We are trying to localize the gaseous molecules in a region & hence hence the uncertainty in it's momentum rises & hence the temperature. because they are inter related.

Answer 28

The temperature is rising according to this formula\[PV=nRT\] P=Pressure, V is Volume, n is number of moles of substance, R is the gas constant and T is the Temperature
and is to do with the collisions of the molecules

But you are talking about the uncertainty relation for x position and momentum, you are saying the positions are getting more confined the hence the momentum must be increasing ie energy is increasing

Answer 29

I like this concept

and ill think abut what you have said


but im am going to have to get some sleep as it late where i am

Answer 30

Yeah i was aware of that explanation but i am asking what influenced the molecules to increase their kinetic energy? Is it because of uncertainty. because the temperature of the molecules is interrelated to their kinetic energy & velocity?

Answer 31

ok thanks you a lot. You were awesome:)

Answer 32

it is great to have someone to discuss this stuff with

Answer 33

when particles collide the bounce back but waves collide they travel through one another without loss of energy

Answer 34

wow lots of writing on one question