Questions on Atoms (based on from reading some of "Atoms in Motion" - Chapter 1 - Feynman Lectures)

[tylers100]

[note: Hey moderators, I'm not sure whether to post this under here (homework help) or physics section.. which is exactly appropriate for this kind of post? I'm not student, but I'm self-teaching (non-formal education) to learn physics for time being.]

Location of Atoms

1. "Everything is made of atoms" sentence was mentioned on the 11th paragraph, 1-4 chemical reactions. So does that mean the universe is 100% fully made of atoms which are evenly located and "distributed" in every directions (although not in a perfect matrix structure order).. there is no such as absolutely empty vacuum space, devoid of atoms?

Shape Definitions on Atoms

2. Are all kinds of atoms' actual shape pretty much undefined as these are the smallest things and can't really be directly seen on any microscopes. Only that the properties and indirect evidences from atoms are known from experiments? On 9th paragraph, 1-4 chemical reactions, there is a "somewhat" direct evidence (Brownian motion example) but that still is not absolutely direct evidence though. I remember reading somewhere on the Internet that there is sort of cloud-alike surrounding the nucleus of the atom, called electrons. Why the cloud word? Is it because the electrons are best imagined like cloud or is it an expressive term to conceptually describe a difficult and undefined shape of electrons located around about the nucleus?

Behaviours of Atom

3. An atom with different numbers of protons/neutrons and electrons will determine which types of atom and how many atoms it will attract with?

4. Are attracting and repelling behaviours between atoms the only "mechanical actions" that any atom can do?

5. Do the repelling behaviour only happen because of the in-compatibility factor of properties between each of the atoms?

6. Do each of the atoms actually exert a "negative gravity" force against a mismatching atom when repelling? (and / or exert a positive gravity when attracting?)

7. Are the force(s) between atoms simply called interactions?

8. What are the force(s) between atoms made of? Elementary particles, more specifically the gauge bosons group I presume?

9. Which govern the force(s) between atoms; electrons or nucleus? I mean, the electrons would be responsible for "attracting" to another electrons of an atom? But.. I wonder, the numbers of electrons would only exist according to the nucleus. After all, without nucleus there would be no electrons? If yes, then is nucleus ultimately the one that governs the interactions between atoms?

10. What fuel/energize the atom to attract at first place? Is it motion? If yes, then since motion is caused by temperature.. which is ultimately caused by source of energy?

Energy, Temperature, and Motion of Atom

11. Is higher temperature only thing that cause a motion in an atom?

12. Energy -> Temperature -> Motion. Are everything and / or us are generally always at motion (speaking at atomic level)?

13. What exactly is energy? (I know the general meaning, but not properties or deeper meaning of the energy word when used in physics or science.. sort of strict sense or something like that.)

[swansont]

[note: Hey moderators, I'm not sure whether to post this under here (homework help) or physics section.. which is exactly appropriate for this kind of post? I'm not student, but I'm self-teaching (non-formal education) to learn physics for time being.]

 

 

Location of Atoms

 

1. "Everything is made of atoms" sentence was mentioned on the 11th paragraph, 1-4 chemical reactions. So does that mean the universe is 100% fully made of atoms which are evenly located and "distributed" in every directions (although not in a perfect matrix structure order).. there is no such as absolutely empty vacuum space, devoid of atoms?

Not evenly located. Atoms are clustered in planets and stars, and those grouped in galaxies.

 

On a planet like earth, atoms are generally denser in solids and liquids than in gases.

 

Shape Definitions on Atoms

 

2. Are all kinds of atoms' actual shape pretty much undefined as these are the smallest things and can't really be directly seen on any microscopes. Only that the properties and indirect evidences from atoms are known from experiments? On 9th paragraph, 1-4 chemical reactions, there is a "somewhat" direct evidence (Brownian motion example) but that still is not absolutely direct evidence though. I remember reading somewhere on the Internet that there is sort of cloud-alike surrounding the nucleus of the atom, called electrons. Why the cloud word? Is it because the electrons are best imagined like cloud or is it an expressive term to conceptually describe a difficult and undefined shape of electrons located around about the nucleus?

It's an apt analogy. Where electrons can be found is described by probabilities, with the details depending on their energy and angular momentum states.

[imatfaal]

1. Everyday, ordinary matter is made of atoms. Atoms are not evenly distributed throughout the universe (apart from on the largest scale - ie if you look at the whole observable universe in one shot). The gaps between stuff in pace are just that - gaps. You might get the a few rare atoms of Hydrogen - but not much.

 

2. We can image - to an extent - nowdays. Much of this section will be explained in great detail later on in the lectures - sit tight

 

3. Atoms with different numbers of protons are called different elements. With different numbers of neutrons but same number of protons are called isotopes. And with different numbers of only electrons are called ions.

 

4. Atoms will interact electromagnetically when they have lost, gained or shared an electron, they will interact gravitationally (although very weak compared to EM) because they have mass, some will decay (eg Carbon 14 to Nitrogen 14) when some of the internal particles undergo processes governed by the weak force, they dont interact with other atoms via the strong force - but it is the strong force that holds their components together - and the residual strong force that forms those components into the nucleus

[swansont]

Behaviours of Atom

 

3. An atom with different numbers of protons/neutrons and electrons will determine which types of atom and how many atoms it will attract with?

 

4. Are attracting and repelling behaviours between atoms the only "mechanical actions" that any atom can do?

 

5. Do the repelling behaviour only happen because of the in-compatibility factor of properties between each of the atoms?

 

6. Do each of the atoms actually exert a "negative gravity" force against a mismatching atom when repelling? (and / or exert a positive gravity when attracting?)

 

7. Are the force(s) between atoms simply called interactions?

 

8. What are the force(s) between atoms made of? Elementary particles, more specifically the gauge bosons group I presume?

 

9. Which govern the force(s) between atoms; electrons or nucleus? I mean, the electrons would be responsible for "attracting" to another electrons of an atom? But.. I wonder, the numbers of electrons would only exist according to the nucleus. After all, without nucleus there would be no electrons? If yes, then is nucleus ultimately the one that governs the interactions between atoms?

 

10. What fuel/energize the atom to attract at first place? Is it motion? If yes, then since motion is caused by temperature.. which is ultimately caused by source of energy?

The force is electrostatic (gravity can be safely ignored), primarily from the electron configuration. But your point true; you need the nucleus to have an atom in the first place. There is no energy "fuel" necessary for this. Charges attract or repel, and there is a certain amount of energy in a particular configuration, but once there it does not need energy to maintain that configuration.

 

 

 

Energy, Temperature, and Motion of Atom

 

11. Is higher temperature only thing that cause a motion in an atom?

 

12. Energy -> Temperature -> Motion. Are everything and / or us are generally always at motion (speaking at atomic level)?

 

13. What exactly is energy? (I know the general meaning, but not properties or deeper meaning of the energy word when used in physics or science.. sort of strict sense or something like that.)

Energy is a property of atoms or systems; it tells us the capacity to do work (in a physics sense).

 

Temperature ignores the center-of-mass motion of a system. Throwing a brick does not change its temperature, but all of the atoms will have that motion added to the random vibrations they have owing to being at some temperature. That vibrational motion is always there, in some amount. No way to completely stop it.

[imatfaal]

5. They repel when they are ions and both the same charge - attract if different charges. They also repel if you try and force them too close together - until very very close. Not sure what incompatibility means in this context. Some atoms are much more stable (ie are likely to end up in this state if left it own devices) when bound closely with another atom of the same element (ie Oxygen, Hydrogen)

6. No such thing as negative gravity as far as I know - stick to the lectures, they are gold-dust.

7. Not all interactions are forces

 

8. That is way way more complicated than you need to be getting to grips with at the moment. Stick to the plan of taking it one step at a time - you can be a long way through a physics degree before you need to consider gauge bosons.

9. In most case electrons do not attract other electrons (like charges repel) - but the presence of an electron and the gap where an electron should be can mean that the two atoms can be more stable together than apart. You get electrons without nuclei - rays of electrons used to be what made TV screens work.

[Sensei]

Shape Definitions on Atoms

 

2. Are all kinds of atoms' actual shape pretty much undefined as these are the smallest things and can't really be directly seen on any microscopes. Only that the properties and indirect evidences from atoms are known from experiments?

We can see electrons and alpha particles (Helium-4 nucleus), and other highly accelerated ions, in Cloud Chamber device.

When they're passing through chamber, they ionize medium (mixture of alcohol with air) and leave visible trace.

You can see it on YouTube videos:

 

 

 

Or you can even build your own particle detector for 50 usd or so, following instructions given here

http://www.ultimate-theory.com/en/2014/6/8/how-to-build-cloud-chamber-particle-detector

Edited March 17, 2015 by Sensei

[tylers100]

swansont and imatfaal: About the gaps between atoms (or clusters of atoms)... the gaps are gaps.. nothingness itself in absolute sense? If yes, then what I always thought about the empty space between atoms or clusters of atoms is wrong. I always thought there must be other different atoms or particles existing.. occupying in all gaps or empty space areas because... surely that would help propagate or mediate interactions and / or forces between atoms or particles? If gaps are in fact just empty or nothing in absolute sense, then it must be interesting to learn and understand how atoms or particles' interactions and / or forces work through or around that. Or am I just thinking a bit too hard about the empty space or nothing?

Ok. I haven't moved on past to other lectures, I'm still on atoms. I have decided to try be a bit careful and I'm taking it one step at a time.

I'm still reading the replies from you guys.. back and forth, visiting wikipedia and other websites.

I'm learning a bit more in depth about the conceptual structural model of an atom, term words for component parts of it, and how it work (very basic only). I have chosen the oxygen atom, but is it good idea to use the oxygen atom as example to "generally and universally" describe the structural and component parts of other atoms?

The very basic make-up of an atom as I can understand so far.. consists of: electron and nucleus (proton and neutron).. (but the isotope of hydrogen (protium) has only one proton, so that must be one of exceptions? reference link: hydrogen)

Now for oxygen atom example:

Each oxygen atom has 8 electrons (negative charge), nucleus containing 8 protons (positive charge) and 8 neutrons (neutral).

1. So each of other different atoms is generally like that... having different amount number of electrons, protons, and neutrons that make it to be different from each of other different atoms? I'm also keeping in mind about the isotopes of element (nucleus) in each of different atom. Is the isotope of element sorta same as the original atom (ie because of same # of protons or atomic number) but with different # of neutrons.. reference link: Isotope

2. If the question #1 (first sentence) is true, then do that factually mean the fundamental interactions (Electromagnetism, Gravity, Strong, and Weak) behave differently in each of different atoms? I kind of suspect it is obviously yes, but I just want to make absolutely sure. (note: I think this question is a bit too ahead or far for my current understanding as I've yet to understand those fundamental interactions in depth but I still want to have a very basic understanding of what those are for time being.)

3. If the question #2 is true, then that makes sense. Different atoms with fundamental interactions behaving differently in each of these... all of that complicate things and make results (ie universe). That makes me think about causality, it definitely must be the universal truth of how universe work.

[imatfaal]

 

swansont and imatfaal: About the gaps between atoms (or clusters of atoms)... the gaps are gaps.. nothingness itself in absolute sense? If yes, then what I always thought about the empty space between atoms or clusters of atoms is wrong. I always thought there must be other different atoms or particles existing.. occupying in all gaps or empty space areas because... surely that would help propagate or mediate interactions and / or forces between atoms or particles? If gaps are in fact just empty or nothing in absolute sense, then it must be interesting to learn and understand how atoms or particles' interactions and / or forces work through or around that. Or am I just thinking a bit too hard about the empty space or nothing?

...

 

To give you an idea of how many atoms/molecules are in things; I have a litre of water on my desk.

 

• The litre of water is around 3x10²⁵ molecules of H₂O
• If the bottle was filled with dry room temperature air it would have about 2.53x10²² molecules in it (a factor of a thousand less)
• If the bottle was in the interstellar spaces within our galaxy - but not near any stars then there would be between a million 10⁶ and a trillion 10¹² particles in it (that's the molecular clouds)
• If the bottle was on the very outskirts - in the galactic corona then you would average around one particle in the bottle
• and if the bottle was in the intergalactic spaces that separate clusters and galaxies you would need thousands of bottles to have a chance of finding one particle.

[tylers100]

Sensei: Thanks for the youtube video clips. Kinda very cool things to watch.

I do not know or understand fully how it work but Heh I wonder if there is any way that we could somehow safety adapt the method to see traces of particles like on those video clips.. to "dye" air atmosphere, then the dye would somehow attach to electrons or other sub-atomic particles of atoms such as oxygen or nitrogen (the nitrogen is better since the large percent number of it is everywhere than oxygen), after that we'd see something similar to video clips. Man, it'd be amazing or even awesome but then afterward a period of time it'd drive some or all of us to crazy or something like that.. as we wouldn't really function with clouds appearing everywhere all around about us (ie can't see very well)

I'm definitely not ready to purchase and build my own particle detector as I'm still learning science/physics. But I have bookmarked it for future reference.

[swansont]

 

swansont and imatfaal: About the gaps between atoms (or clusters of atoms)... the gaps are gaps.. nothingness itself in absolute sense? If yes, then what I always thought about the empty space between atoms or clusters of atoms is wrong. I always thought there must be other different atoms or particles existing.. occupying in all gaps or empty space areas because... surely that would help propagate or mediate interactions and / or forces between atoms or particles? If gaps are in fact just empty or nothing in absolute sense, then it must be interesting to learn and understand how atoms or particles' interactions and / or forces work through or around that. Or am I just thinking a bit too hard about the empty space or nothing?

 

At the level you're investigating, there is nothing in between the atoms. Using more advanced physics, you will find that this "empty space" actually has some properties, so "empty" is not really the right way to describe it. Forces, light, and the particles themselves do not need any sort of medium to travel through. There's some important and interesting physics related to this.

[Sensei]

I do not know or understand fully how it work

Cloud chamber is typically used (for 100 years) for visualizing decay of radioactive elements.

 

They decay via couple methods:

Beta decay minus (emitting electron & antineutrino)

http://en.wikipedia.org/wiki/Beta_decay

 

Beta decay plus (emitting positron & neutrino)

http://en.wikipedia.org/wiki/Positron_emission

 

Double beta decay minus (two electrons at the same time)

Double beta decay plus (two positrons at the same time)

 

Proton emission

http://en.wikipedia.org/wiki/Proton_emission

 

Neutron emission

http://en.wikipedia.org/wiki/Neutron_emission

 

Alpha decay

http://en.wikipedia.org/wiki/Alpha_decay

 

And few more rare decay modes.

 

but Heh I wonder if there is any way that we could somehow safety adapt the method to see traces of particles like on those video clips..

That's done for hundred years..

 

to "dye" air atmosphere, then the dye would somehow attach to electrons or other sub-atomic particles of atoms such as oxygen or nitrogen (the nitrogen is better since the large percent number of it is everywhere than oxygen), after that we'd see something similar to video clips. Man, it'd be amazing or even awesome but then afterward a period of time it'd drive some or all of us to crazy or something like that.. as we wouldn't really function with clouds appearing everywhere all around about us (ie can't see very well)

It's impractical for Nitrogen & Oxygen. They are approximately 28 and 32 more heavy than proton. Thus far more energy is needed to accelerate them.

 

I'm definitely not ready to purchase and build my own particle detector as I'm still learning science/physics. But I have bookmarked it for future reference.

See instruction at website. It's extremely easy.

[swansont]

I'm learning a bit more in depth about the conceptual structural model of an atom, term words for component parts of it, and how it work (very basic only). I have chosen the oxygen atom, but is it good idea to use the oxygen atom as example to "generally and universally" describe the structural and component parts of other atoms?

 

The very basic make-up of an atom as I can understand so far.. consists of: electron and nucleus (proton and neutron).. (but the isotope of hydrogen (protium) has only one proton, so that must be one of exceptions? reference link: hydrogen)

 

Hydrogen is the only example of having zero neutrons as a possible isotope, except as a paper exercise. (i.e. you could talk about He-2 but you'll never find it except as a transient state in some nuclear interaction)

 

Now for oxygen atom example:

 

Each oxygen atom has 8 electrons (negative charge), nucleus containing 8 protons (positive charge) and 8 neutrons (neutral).

 

1. So each of other different atoms is generally like that... having different amount number of electrons, protons, and neutrons that make it to be different from each of other different atoms? I'm also keeping in mind about the isotopes of element (nucleus) in each of different atom. Is the isotope of element sorta same as the original atom (ie because of same # of protons or atomic number) but with different # of neutrons.. reference link: Isotope

 

2. If the question #1 (first sentence) is true, then do that factually mean the fundamental interactions (Electromagnetism, Gravity, Strong, and Weak) behave differently in each of different atoms? I kind of suspect it is obviously yes, but I just want to make absolutely sure. (note: I think this question is a bit too ahead or far for my current understanding as I've yet to understand those fundamental interactions in depth but I still want to have a very basic understanding of what those are for time being.)

 

3. If the question #2 is true, then that makes sense. Different atoms with fundamental interactions behaving differently in each of these... all of that complicate things and make results (ie universe). That makes me think about causality, it definitely must be the universal truth of how universe work.

 

The rules are the same, but the results are different. Different isotopes have different masses, so that affects chemical reaction rates and has small effects on the energy of the electron states, so there are (generally) small differences in their spectra. Changing the numbers of neutrons has a much larger effect on the behavior of the nucleus; some isotopes are stable, while others are not.

[Strange]

1. So each of other different atoms is generally like that... having different amount number of electrons, protons, and neutrons that make it to be different from each of other different atoms? I'm also keeping in mind about the isotopes of element (nucleus) in each of different atom. Is the isotope of element sorta same as the original atom (ie because of same # of protons or atomic number) but with different # of neutrons.. reference link: Isotope

 

Exactly. The chemical properties of an atom are defined by the electrons. Mainly by the outermost electrons. And, at the level you are at, just by the number of electrons in the outermost "shell". It is slightly more complicated than that and as you go deeper it just gets more complicated! But you can get a very long way with the simple model.

 

Other physical properties, such as the mass, are determined by the nucleus (because protons and neutrons weight about 2,000 times as much as an electron).

 

Isotopes are, as you say, atoms with a given number of protons (and electrons) but a different number of neutrons. The number of neutrons is usually close to the number of protons, for stability reasons (which are not fully understood). Isotopes can have different physical properties (mass, obviously) and be more or less radioactive. The extra mass of the nucleus can also have an effect on the outer electrons and make very small differences to the chemical properties.

2. If the question #1 (first sentence) is true, then do that factually mean the fundamental interactions (Electromagnetism, Gravity, Strong, and Weak) behave differently in each of different atoms? I kind of suspect it is obviously yes, but I just want to make absolutely sure. (note: I think this question is a bit too ahead or far for my current understanding as I've yet to understand those fundamental interactions in depth but I still want to have a very basic understanding of what those are for time being.)

 

No, these fundamental interactions behave the same in all atoms. But the varying numbers of particles can change the resulting effects we see. For example, although the weak interaction is responsible for beta decay, whether or not that occurs depends on the numbers of protons and neutrons. And the electromagnetic forces are always the same, but we see a huge range of chemical reactivity.

[Sensei]

Each oxygen atom has 8 electrons (negative charge), nucleus containing 8 protons (positive charge) and 8 neutrons (neutral).

Not quite.

You're describing just the most abundant isotope of Oxygen: Oxygen-16.

There are two more stable Oxygen isotopes: Oxygen-17 and Oxygen-18.

http://en.wikipedia.org/wiki/Isotopes_of_oxygen

The number of neutrons is usually close to the number of protons, for stability reasons (which are not fully understood).

This is true only for the first 20 elements.

Ca-40 is the last one with even quantity of protons and neutrons.

Sc-42 is unstable.

Ti-44 is unstable.

V-46 is unstable.

 

Isotopes can have different physical properties (mass, obviously) and be more or less radioactive. The extra mass of the nucleus can also have an effect on the outer electrons and make very small differences to the chemical properties.

Little difference of isotope property, might mean huge difference for living organisms.

The most of multicellular organisms are dying after drinking heavy water for too long (with Deuterium isotope instead of Hydrogen).

Edited March 18, 2015 by Sensei

[Strange]

This is true only for the first 20 elements.

Ca-40 is the last one with even quantity of protons and neutrons.

Sc-42 is unstable.

Ti-44 is unstable.

V-46 is unstable.

 

I seems that when I said "close" I meant not very close...

 

The most of multicellular organisms are dying after drinking heavy water for too long (with Deuterium isotope instead of Hydrogen).

 

I wasn't aware of the toxic effects. More here: http://en.wikipedia.org/wiki/Heavy_water#Effect_on_biological_systems

Sounds like a particularly nasty way to kill someone (if it is possible). I wonder if anyone has ever used it in a crime story. I guess it would be hard to detect unless you were looking for it specifically.

 

It isn't surprising that the difference between hydrogen and deuterium would be more significant than other elements as it doubles the mass of the nucleus.

Edited March 18, 2015 by Strange

[studiot]

Tylers,

 

This is all getting very complicated.

 

One simple distinction you should know is the difference between atoms and molecules.

 

All atoms are molecules.

But not all molecules are atoms.

 

Molecules are the smallest unit of any substance (ie matter).

The definition of any pure substance is that all the molecules are the same.

 

Some molecules can be broken down further but the results are not the original substance but atoms.

 

Atoms are molecules of special substances, known as elements.

These cannot still be broken down further and remain as matter.

 

All molecules are made of slightly less than 150 known elements.

 

Some elements exist in normal conditions as multiple atoms of the same element forming molecules.

Examples are oxygen and hydrogen.

 

A combination of oxygen and hydrogen exists as the water molecule.

 

Helium normally exists molecules comprising a single atom.

 

Hope this helps.

[Strange]

I found that rather confusing ... and I studied chemistry

 

I have always considered molecules as consisting of more than one atom (but a web search shows that definitions vary).

[Sensei]

Molecules-compounds don't have to be made of ordinary proton-neutron matter.

 

See f.e. exotic atoms: positronium, pionium, antiprotonic Helium.

http://en.wikipedia.org/wiki/Positronium

http://en.wikipedia.org/wiki/Pionium

http://en.wikipedia.org/wiki/Antiprotonic_helium

 

They can enter into reaction with regular matter (and compounds), forming chemical compound, for a fraction of second.

 

Muonium article mentions MuCl compound (muonium chloride) and NaMu compound

http://en.wikipedia.org/wiki/Muonium

Which is like HCl

 

All molecules are made of slightly less than 150 known elements.

There is known 118 elements.

2+8+8+18+18+32+32 = 118.

 

I wrote computer application for learning them all in human memory.

Edited March 18, 2015 by Sensei

[studiot]

Sensei and strange, sounds like you two are quibbling.

 

This is meant to be basic and elementary to present concepts and promote understanding.

 

What exactly did you not understand?

[Strange]

 

What exactly did you not understand?

 

I found your description of the relationship between molecules and atoms and elements confusing. I think it is all correct (for the appropriate definition of "molecule") but requires some thought to make sense of. This is arguably a good thing, as having worked through it, the ideas may stick better.

 

(I think Sensei's introduction of non-standard atomic structures is likely to add to the OP's confusion rather than reduce it. But it is interesting stuff.)

[tylers100]

Ok, I'm beginning to understand a bit more about what atom is and how it work in very basic way.

Last few questions before I move on to other lectures and / or topics:

1. What "power" or "energize" a particle to "cause and effect" (ie interactions) on another particle?

2. And what originated it at first place?

[swansont]

 

I have always considered molecules as consisting of more than one atom (but a web search shows that definitions vary).

 

As have I. Any single atom would not be considered a molecule, according to how I learned it.

 

Ok, I'm beginning to understand a bit more about what atom is and how it work in very basic way.

Last few questions before I move on to other lectures and / or topics:

1. What "power" or "energize" a particle to "cause and effect" (ie interactions) on another particle?

2. And what originated it at first place?

 

 

Atoms may spontaneously interact and form a compound if that will result in a lower energy state. Sometimes they need some kinetic energy to get close enough to do this. The interaction will be due to the electrons (electromagnetic interaction) but there are different kinds of bonds they can form. It depends on the atoms involved.

[Sensei]

 

As have I. Any single atom would not be considered a molecule, according to how I learned it.

 

Except Noble gases.

[pavelcherepan]

 

Except Noble gases.

That one is a bit weird - in the article on monoatomic gases on wiki it says "The only stable single atom molecules at standard pressure and temperature are noble gases", yet in the article on molecules it defines molecules as "consisting of two or more atoms held together by chemical bonds". Those seem to contradict one another. Edited March 20, 2015 by pavelcherepan

[swansont]

 

Except Noble gases.

 

I was always taught that noble gases don't form molecules. I wonder if there is a geographic dependence on the definitions used here.