Aggregated states of the substance

Content and key concepts

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Alterna · physics · 1.3
Aggregated states of the substance
The interaction of molecules, solid bodies, fluids, gases, crystal grate.
Ice, water, and steam are the same substance in different states. The difference is in the movement of molecules and the distance between them. Let's see why a solid body remains in shape and the gas fills the room.
GEF · Grade 7
FOP · basic level
01
Mutual gravity and repulsion of molecules
Why don't the solid bodies fall apart and the gases fill the whole volume?
Inter-molecular forces
The molecules operate simultaneously.
two forces
: pull and push.
Prix
long distances
- the attraction is weak
Prix
distance r0
(balanced) — Balanced
Prix
r < r₀
- Repelling is rising sharply
Prix
r > r₀
- it grows, then it loses.
It's the gravity of molecules that keeps solid bodies and fluids, and in gas, the distance between molecules is great, and the gravity is almost invisible.
📈
The forces of attraction and repulsion
IV-008 · schedule of the interaction force from distance
Distance r:
1.5
r₀
02
Aggregated states of the substance
Solid, liquid, gaseous - three states of the same substance.
Three aggregate states
Property
Hard
Liquid
Gas
Form
Permanent
Accepts the shape of the receptacle
Fills the vessel
Interpretation
Permanent
Permanent
Fills the vessel
Distance between molecules
Small (ER0)
Small (ER0)
Large (~r0)
Movement of molecules
Momentations around the position
Swings
Chaotic
Order
Crystal bars
The Middle East
The mess.
Crystal bars
In solid bodies, atoms (or molecules) are placed in strict order — they form
Crystal bars
Each atom fluctuates around its position, but does not leave it, so solid bodies retain shape.
🛡
Comparison of aggregate states
IV-009 · click on the cell to see the structure
Hard
Liquid
Gas
Form
Permanent
Form of receptacle
Fills the vessel
Interpretation
Permanent
Permanent
Fills the vessel
Moleculars
Scratch
Moves
Chaotic
Please click on the table box
03
Outcome of the chapter
Key concepts
The substance shall consist of:
molecules
(or atoms) between them are spaced.
The Brown Movement
- Chaotic movement of particles under molecule impacts
Diffuse
- spontaneous mixing of substances; faster in gases, slower in solid bodies; accelerated by heating
Power between molecules
attractions and repulsion
Three aggregate states:
firm
(screams)
Liquid
(volume without shape)
Gas
(no shape and volume)
C
What needs to be understood
Outcome 1
Explain the physical meaning of the topic "Aggregate states of the substance" through the model, not just through the formula.
Outcome 2
Clear and correct use of terms: solid body, liquid, gas.
Outcome 3
Indicate the conditions for the applicability of the law, verify units and limit cases.
T
Terms of the topic
The definition should indicate the physical meaning, not a substitute for a domestic synonym.
solid body
The state of the substance, which usually retains its own shape and volume through the connections between particles.
Liquid
The state of the substance that retains the volume but takes the shape of the receptacle and can leak.
Gas
The state of the substance that does not retain its own shape and volume and fills an accessible vessel.
Crystal grate
Periodically organized particle placement in the crystal.
Amorphous Body
A solid body without a long order in the location of the particles and without a single melting point.
F
Origin and conclusion of the formulas
The fundamental law cannot be "proven" by algebras: for each record, it is stated whether it is a definition, an experimental law, or a model effect.
Qualitative theme
The main content of this topic is expressed by models, observations and causal relationships; the formula is not artificially added: quantitative laws are introduced on connected pages.
!
Model boundaries and typical errors
Error: Forget model condition
You can't change the formula to any situation just because the letters match. The key condition of this topic is that, in long distances, gravity is weak.
How to Check the Mind
At r0 (balanced), the forces are balanced and then check the units, vector direction, and result behaviour at zero or very large parameter.
Σ
Conclusion on the topic
Aggregated states of the substance
Ice, water, and steam are the same substance in different states. The difference is in the movement of molecules and the distance between them. Let's see why a solid body remains in shape and the gas fills the room.
At long distances, gravity is weak.
At r0 (balanced) - balanced forces
Any numerical result shall be accompanied by a unit, a sign and an explanation of its physical meaning.
The content is consistent with the FRP on Physics of the OS/OSS 2025 and the subject matter of the current lines of the PNP: I. M. Peryškin and co-authors (7–9), G. J. Mäkishev and coauthors (10–11), and with the lines "Engineers of the Future" and V. A. Kasyanov. The original texts are not reproduced, the text of the textbooks is not reproduced.