Why Do Liquids Behave Differently Than Solids?

  • Context: High School 
  • Thread starter Thread starter R Power
  • Start date Start date
  • Tags Tags
    Liquids
Click For Summary

Discussion Overview

The discussion centers on the behavior of liquids compared to solids, exploring the underlying reasons for their differing properties, such as flowability and density. Participants examine concepts related to molecular bonding, thermal expansion, and specific characteristics of substances like water and ice.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions the relationship between density and the state of matter, suggesting that flowability does not solely depend on density.
  • Another participant proposes that the behavior of solids and liquids is influenced by the strength of bonds between atoms or molecules, with stronger bonds in solids leading to a more rigid structure.
  • A participant raises a question about the behavior of water and ice when subjected to heat and cooling, noting an apparent contradiction in expected density changes.
  • One response attributes the unique behavior of water to the formation of hydrogen bonds, explaining how these bonds affect molecular arrangement as temperature changes.
  • Another participant reiterates the unusual property of water expanding when frozen, linking it to hydrogen bonding.
  • A later reply introduces the concept of supercooled liquids, mentioning that glass shares similar properties with water regarding heat and expansion.

Areas of Agreement / Disagreement

Participants express various viewpoints regarding the properties of liquids and solids, particularly concerning water's behavior. There is no consensus on the explanations provided, and multiple competing views remain regarding the underlying principles.

Contextual Notes

Some claims rely on specific definitions of bonding and states of matter, and the discussion includes unresolved questions about the behavior of water and ice under different thermal conditions.

R Power
Messages
270
Reaction score
0
Hi
Why liquids behave as they do?
I mean many sloids have density greater than some liquids e.g ice - water but still ice is solid and water liquid. This means flowability doesn't depend only on density. Then on what it depends?
I mean how will you answer that why is this/that substance a liquid.
 
Physics news on Phys.org
It all depends on the bonds between the atoms/molecules of the substance.
In a solid they are strongly attached to each other, crystals eg diamond, have the strongest bonds between atoms and are the most solid-like of solids. Graphite has weaker bonds and so is softer and behaves a little more like a liquid.

In liquids there are only very weak bonds between different molecules
 
why water expands when cooled or why ice contracts when given heat?
on giving heat moleclules should slip away from each other and density should decrease!
 
Because of formation of hydrogen bonds.When water is cooled to 4°C, the molecules get close enough that a hydrogen atom of one molecule is bonded to oxygen of another as they develop partial charges due to difference of electronegativity.The molecules rearrange according to the bond energy as the sample goes on cooling.
 
Water is rather odd - it's the only material that expands when frozen, due as vin says, to hydrogen bonds.
 
mgb_phys said:
Water is rather odd - it's the only material that expands when frozen, due as vin says, to hydrogen bonds.

All "super cooled liquids" contract with heat and expand when cooled.
Glass is a super cooled liquid with the same properties as water where heat and expansion is concerned.
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 11 ·
Replies
11
Views
5K
  • · Replies 32 ·
2
Replies
32
Views
4K
Replies
8
Views
2K
  • · Replies 23 ·
Replies
23
Views
3K
  • · Replies 32 ·
2
Replies
32
Views
4K
  • · Replies 9 ·
Replies
9
Views
2K