Why one substance does not pass through another substance?

In summary, the conversation discusses the atomic structure of books and desks and how they interact with each other. It is mentioned that if there are few atomic cores in the objects, they may pass through each other, but in reality, they are stably placed on top of each other. The explanation for this is that the outer electrons of the objects repel each other, and the solid materials they are made of are elastic and maintain their shape. It is also mentioned that in order for two objects to pass through each other, a large amount of energy is needed to break the chemical bonds that hold them together. The possibility of one object becoming embedded in the other is also discussed, but it is noted that this is more likely to happen on a
  • #1
obiscr
3
2
TL;DR Summary
The problem of nuclei passing through each other.
1. Books and desks have only one atomic core

IMG_0970.PNG


There is a book and desk, suppose the book and desk are composed of atomic atomic core and extranuclear electrons.

Now, the book moves down along the y axis, while the desk stands still or moves up.

Now there is a problem: the position of the x-axis corresponding to the atomic core of the book is 1, and the position of the x-axis corresponding to the outer electron of the book is 3; the position of the x-axis atomic core corresponding to the desk is 2, and the x-axis corresponding to the desk outside the atomic core The position of the electron is 4. In this case, the book and the desk will pass through each other, and the book will not be stably placed on the desk.

The above is when there are few atomic core in books and desks.

2. Books and desks have multiple atomic core

IMG_0979.jpg

Assuming that there are many atomic core in the book and desk, the possibility of collision between the atomic core in the book and desk is also greater. At this time, this situation will occur: a part of the atomic atomic core collides, and the force generated between the atomic atomic core overcomes the universal gravitation, which makes the book unable to move down along the y axis. The phenomenon is that the book is inlaid on the table. Of course, the depth of the inlays may not be the same, and at the same time they are unlikely to pass through each other.

But what we encounter in the real world is that the book can be stably placed on the table. There will never be a situation where a book is embedded in a table.

I have always been curious about why this is, and I don’t know if anyone can answer this question. Is there a problem with my way of understanding this question?

Thank you!
 
Last edited:
  • Like
Likes Delta2
Physics news on Phys.org
  • #2
Welcome to PF.
That is a good question.

There are many atomic cores, but they are very small and on the inside. The atomic cores never meet. The outer electrons of one object first meet and repel the outer electrons of the other. That is the normal situation for books on desks in Earth's gravity.

Solid materials are elastic. When you place a book on a desk, they both deform slightly due to the forces on the objects. A book does sink into a desk. https://en.wikipedia.org/wiki/Young's_modulus

A solid material is a network of strong chemical bonds that connect the atoms and maintain the shape of the solid material. Books and desks are usually made from cellulose which is a polymer chain, strong enough to keep trees standing.

As two solid materials are increasingly forced together, if the bonds do not all break so the structure collapses, then the objects may become welded together.

In order for one solid bonded object to fall through another it is necessary to first break half of the chemical bonds. That will take a huge amount of energy. As one object passes through the other they will form a chemical compound, an alloy or a flowing liquid. What remains will be the original material, but will not be in the shape of the original objects.
 
  • Informative
  • Like
Likes berkeman, obiscr, Klystron and 4 others
  • #3
obiscr said:
The phenomenon is that the book is inlaid on the table. Of course, the depth of the inlays may not be the same, and at the same time they are unlikely to pass through each other.

But what we encounter in the real world is that the book can be stably placed on the table. There will never be a situation where a book is embedded in a table.
Suppose that there is wet paint or glue on the table. Then as you press the book on the table, molecules of the paint pass into the book. As the paint, lacquer or glue dries, would you call the book embedded in the table/paint layer which is part of the table?
 
  • Wow
Likes Delta2
  • #4
snorkack said:
Suppose that there is wet paint or glue on the table. Then as you press the book on the table, molecules of the paint pass into the book. As the paint, lacquer or glue dries, would you call the book embedded in the table/paint layer which is part of the table?
Yes, I think it might be like this on a microscopic level.
 
  • Like
Likes Delta2
  • #5
obiscr said:
Yes, I think it might be like this on a microscopic level.
The thing here is that you can pass a liquid through a sieve, cloth, paper etc. and have the liquid reconstitute on the other side because the atoms in the individual sieve threads, cloth or paper fibres are more strongly bonded to other atoms in the fibre and less strongly to the atoms of the fluid between the threads.
In order to pass through microscopic solid, like activated carbon or silica gel, the solid needs bonds that are stronger than bonds to the percolating fluid.
 
  • Like
Likes obiscr
  • #6
snorkack said:
The thing here is that you can pass a liquid through a sieve, cloth, paper etc. and have the liquid reconstitute on the other side because the atoms in the individual sieve threads, cloth or paper fibres are more strongly bonded to other atoms in the fibre and less strongly to the atoms of the fluid between the threads.
In order to pass through microscopic solid, like activated carbon or silica gel, the solid needs bonds that are stronger than bonds to the percolating fluid.
Got it. Thanks!
 

Related to Why one substance does not pass through another substance?

1. Why can't water pass through oil?

Water and oil are immiscible substances, meaning they cannot mix together. This is due to their different molecular structures. Water molecules are polar, meaning they have a positive and negative end, while oil molecules are nonpolar. This difference in polarity causes water and oil to repel each other, making it difficult for them to pass through one another.

2. Why does a membrane only allow certain substances to pass through?

Membranes are selectively permeable, meaning they only allow certain substances to pass through while blocking others. This is because of the membrane's structure, which is made up of tiny pores or channels. These pores are specific in size and shape, allowing only certain molecules to pass through based on their size and polarity.

3. Why can't gases pass through solids?

Gases and solids have different molecular structures. Solids have tightly packed molecules that do not allow for much movement, whereas gases have loosely packed molecules that can move freely. This difference in molecular structure makes it difficult for gases to pass through solids, as they cannot easily fit through the small spaces between solid molecules.

4. Why does a substance dissolve in one solvent but not another?

Dissolving is a process in which a solute (substance being dissolved) breaks apart and disperses evenly in a solvent (liquid in which the solute is dissolved). This process depends on the polarity of the solute and solvent. Like dissolves like, meaning polar solvents can dissolve polar solutes, and nonpolar solvents can dissolve nonpolar solutes. If the solute and solvent have different polarities, they will not be able to interact and dissolve in each other.

5. Why can't larger molecules pass through smaller pores?

Pore size plays a significant role in the movement of molecules through substances. Larger molecules have a harder time passing through smaller pores because they are too big to fit through. This is similar to trying to fit a large object through a small opening. The size of the pores determines which molecules can pass through, and larger molecules will be blocked by smaller pores.

Similar threads

  • Atomic and Condensed Matter
Replies
5
Views
3K
  • Electromagnetism
2
Replies
36
Views
3K
  • Classical Physics
2
Replies
64
Views
5K
Replies
1
Views
1K
Replies
1
Views
4K
  • Introductory Physics Homework Help
Replies
2
Views
244
Replies
2
Views
938
  • Electromagnetism
Replies
28
Views
2K
Replies
22
Views
2K
Replies
5
Views
1K
Back
Top