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Author Topic: What are the rules for solids, liquids and gases?  (Read 10568 times)

Anastasia.fr.1

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for my homework i have to write the rules for solids liquids and gasses. so far i have

gasses:
You cant see gases.

liquids
are wet

solids:
are hard

are these right? do you know any more?

« Last Edit: 04/03/2008 23:16:30 by chris »


 

Offline ahatto

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Re: What are the rules for solids, liquids and gases?
« Reply #1 on: 01/03/2008 18:37:06 »
I don't know if you have studied it yet but the molecules in gases are further apart than in liquids.  The molecules in a liquid are further apart than in a solid.

You could also think about how easily they move.
 

Anastasia.fr.1

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Re: What are the rules for solids, liquids and gases?
« Reply #2 on: 01/03/2008 18:39:05 »
thank you very much ;D :D :)
 

Offline JimBob

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Re: What are the rules for solids, liquids and gases?
« Reply #3 on: 01/03/2008 18:39:57 »
I don't know if you have studied it yet but the molecules in gases are further apart than in liquids.  The molecules in a liquid are further apart than in a solid.

You could also think about how easily they move.

And how far the molecules can move.
 

another_someone

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Re: What are the rules for solids, liquids and gases?
« Reply #4 on: 01/03/2008 19:04:10 »
I don't know if you have studied it yet but the molecules in gases are further apart than in liquids.  The molecules in a liquid are further apart than in a solid.

You could also think about how easily they move.

In general, this is true, but you cannot actually put numbers to it.

The easiest rules are - if you have a beaker:

  • if you put a gas in a beaker, the gas will leak out of the beaker, and the only way you can keep a gas in a beaker is to put a lid on it.
  • if you have a liquid, you can pour the liquid into the beaker, and it will spread out across the bottom of the beaker, but will not rise out of the top of the beaker (assuming we don't get into capillary action, or superfluidity), so you don't need to put a lid on the beaker to keep the liquid in.
  • if you put a lump of solid into a beaker, it will remain a lump, and will not spread out along the bottom of the beaker.

Ofcourse, as we have seen with your question regarding ketchup, there are all sorts of complexities, such as things that are part one thing and part another.
« Last Edit: 01/03/2008 19:07:31 by another_someone »
 

Offline Professor Gaarder

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Re: What are the rules for solids, liquids and gases?
« Reply #5 on: 01/03/2008 20:15:34 »
and if you'll note, not all gasses are invisible. Example: chlorine
 

Offline Professor Gaarder

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Re: What are the rules for solids, liquids and gases?
« Reply #6 on: 01/03/2008 20:17:03 »
I don't know if you have studied it yet but the molecules in gases are further apart than in liquids.  The molecules in a liquid are further apart than in a solid.

You could also think about how easily they move.

In general, this is true, but you cannot actually put numbers to it.

The easiest rules are - if you have a beaker:

  • if you put a gas in a beaker, the gas will leak out of the beaker, and the only way you can keep a gas in a beaker is to put a lid on it.
  • if you have a liquid, you can pour the liquid into the beaker, and it will spread out across the bottom of the beaker, but will not rise out of the top of the beaker (assuming we don't get into capillary action, or superfluidity), so you don't need to put a lid on the beaker to keep the liquid in.
  • if you put a lump of solid into a beaker, it will remain a lump, and will not spread out along the bottom of the beaker.

Ofcourse, as we have seen with your question regarding ketchup, there are all sorts of complexities, such as things that are part one thing and part another.

but this is only possible if the gas has a lower weight than oxygen. for example, neon, argon, and chlorine would all settle to the bottom of a beaker, unless it has water in it to begin with.
 

another_someone

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Re: What are the rules for solids, liquids and gases?
« Reply #7 on: 01/03/2008 20:26:38 »
but this is only possible if the gas has a lower weight than oxygen. for example, neon, argon, and chlorine would all settle to the bottom of a beaker, unless it has water in it to begin with.

Have you walked into a swimming pool, and smelt the chlorine.  If all the chlorine were to settle at ground level, and your nose was at a level where it was breathing oxygen, then how could you smell the chlorine.

In a different vein, CFCs (ChloroFloroCarbons) are heavier than air, yet they can be found in the stratosphere, where they are claimed to be responsible for causing the hole in the ozone layer.  In fact ozone itself is heavier than air.  Nitrogen is also lighter than oxygen, yet the two are mixed in the atmosphere and not stratified by density.

It is true that heavier gasses tend to be more concentrated lower down, and lighter gasses concentrate higher up, but the nature of all gasses is that they diffuse, so some of the gas will be at all levels (as can be seen in my comments above).

The main issue is that liquids have surface tension that define a surface for the liquid, whereas a gas has no such surface, and so diffuses freely.
« Last Edit: 01/03/2008 20:39:56 by another_someone »
 

Offline Professor Gaarder

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Re: What are the rules for solids, liquids and gases?
« Reply #8 on: 02/03/2008 00:30:46 »
true, but those are exceptions best suited for a meteorologist.

if this homework is as low-key as it sounds, you would do best sticking with the basics-solid=high density=frozen, liquid=mid density=melted, gas=low density=boiled.
 

another_someone

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Re: What are the rules for solids, liquids and gases?
« Reply #9 on: 02/03/2008 00:53:57 »
if this homework is as low-key as it sounds, you would do best sticking with the basics-solid=high density=frozen, liquid=mid density=melted, gas=low density=boiled.

Even that is not true - ice is solid, but in normal conditions, is less dense than water at the same temperature.

Mercury in its liquid phase is pretty dense.  Balsa wood is a solid, but pretty low density.
 

Offline Professor Gaarder

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Re: What are the rules for solids, liquids and gases?
« Reply #10 on: 02/03/2008 02:23:05 »
but that would be a disclaimer. certain cases are different than other cases, but the general rule is solid=higher density.
 

another_someone

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Re: What are the rules for solids, liquids and gases?
« Reply #11 on: 02/03/2008 04:16:03 »
but that would be a disclaimer. certain cases are different than other cases, but the general rule is solid=higher density.

But the point is that you are suggesting merely generalities that have more disclaimers that applicable cases - I certainly would not rely on your definition as something that would define the differences between the phases.

Using the idea that gasses will diffuse, liquids will flow, and solids will remain fixed in position, is a fairly good and consistent definition (not without rare exception, but mostly where you get mixtures of phases).
 

Offline Professor Gaarder

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Re: What are the rules for solids, liquids and gases?
« Reply #12 on: 02/03/2008 05:02:47 »
I'm just telling it how I learned it. Every teacher teaches it different, I s'pose.
 

Offline lightarrow

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Re: What are the rules for solids, liquids and gases?
« Reply #13 on: 02/03/2008 22:35:30 »
for my homework i have to write the rules for solids liquids and gasses. so far i have

gasses:
You cant see gases.

liquids
are wet

solids:
are hard

are these right? do you know any more?



Solids: they have a constant volume and a constant shape. (constant = doesn't vary)

Liquids: have a constant volume but not a constant shape: they take the container's shape.

Gases: don't have constant volume (they take the container's volume) nor constant shape (they take the container's shape).

Edit: I used the term "constant" to make Anastasia understand better; the correct term is "well definite", which means that, once specified temperature, pressure, mass, composition, the property (volume or shape) stay the same.
« Last Edit: 04/03/2008 12:35:43 by lightarrow »
 

Offline lightarrow

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Re: What are the rules for solids, liquids and gases?
« Reply #14 on: 02/03/2008 22:37:46 »
[...]
Ofcourse, as we have seen with your question regarding ketchup, there are all sorts of complexities, such as things that are part one thing and part another.

Are you referring to her father after the experiment?  [8D]
 

lyner

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Re: What are the rules for solids, liquids and gases?
« Reply #15 on: 04/03/2008 10:19:10 »
The problem with this sort of exercise is that it encourages students to think in boxes and categories. Science is full of exceptions and yet Science teaching insists on categories; every day I see confusion because of this.
It's particularly galling when you read the questions and the 'expected' answers in public exam papers. Bad Science!
 

Offline lightarrow

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Re: What are the rules for solids, liquids and gases?
« Reply #16 on: 04/03/2008 12:43:14 »
The problem with this sort of exercise is that it encourages students to think in boxes and categories. Science is full of exceptions and yet Science teaching insists on categories; every day I see confusion because of this.
It's particularly galling when you read the questions and the 'expected' answers in public exam papers. Bad Science!

I agree with you. I consider more useful pedagocically to collect as more informations as possible and then make the student find the most general definition they can find (instead of doing the reverse), but without pretending that general definition to be a dogma. Maybe Anastasia's homework was intended in this sense.
 

another_someone

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Re: What are the rules for solids, liquids and gases?
« Reply #17 on: 04/03/2008 12:50:05 »
I agree with you. I consider more useful pedagocically to collect as more informations as possible and then make the student find the most general definition they can find (instead of doing the reverse), but without pretending that general definition to be a dogma. Maybe Anastasia's homework was intended in this sense.

I think the problem with that assumption is the wording of her question.

If she was merely asked to describe the differences between liquids, solids, and gasses, then you could reasonably surmise that she was merely being asked to describe observed properties in a non-exclusive manner.

The question asked what were the 'rules' for liquids, solids, and gases; implying that she was being asked for definitions rather than merely describing observable differences.
 

Offline Make it Lady

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Re: What are the rules for solids, liquids and gases?
« Reply #18 on: 04/03/2008 20:01:35 »
The problem with this sort of exercise is that it encourages students to think in boxes and categories. Science is full of exceptions and yet Science teaching insists on categories; every day I see confusion because of this.
It's particularly galling when you read the questions and the 'expected' answers in public exam papers. Bad Science!
Learning about science is like peeling an onion. Once you have learnt stuff on one layer you immediately have to peel off another. The homework you were given should teach you the basics of solids, liquids and gases. Once you understand it at this level then you can go onto the exceptions. You should always remember that each rule may be expanded upon later.

Remember the particles in a solid just vibrate as they have less energy than in the other states. Particles in a liquid have slightly more energy so they exchange places but stay close to each other. Gases have more energy so are able to move away from each other. Think of the energy as music. If the music is slow people will dance close together and snog. Faster disco music will make people move about more but stay in little groups. If you put on some fast, mad, wild music everyone will shoot around the room like idiots crashing into each other.   
 

Offline lightarrow

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Re: What are the rules for solids, liquids and gases?
« Reply #19 on: 04/03/2008 22:34:20 »
Learning about science is like peeling an onion. Once you have learnt stuff on one layer you immediately have to peel off another. The homework you were given should teach you the basics of solids, liquids and gases. Once you understand it at this level then you can go onto the exceptions. You should always remember that each rule may be expanded upon later.

Remember the particles in a solid just vibrate as they have less energy than in the other states. Particles in a liquid have slightly more energy so they exchange places but stay close to each other. Gases have more energy so are able to move away from each other. Think of the energy as music. If the music is slow people will dance close together and snog. Faster disco music will make people move about more but stay in little groups. If you put on some fast, mad, wild music everyone will shoot around the room like idiots crashing into each other.   

So how would you explain the fact sulfur becom less fluid increasing the melt sulfur's temperature in the interval 160C - 200C? Its viscosity increases 10,000 times!
 

another_someone

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Re: What are the rules for solids, liquids and gases?
« Reply #20 on: 04/03/2008 22:35:57 »
If the music is slow people will dance close together and snog. Faster disco music will make people move about more but stay in little groups. If you put on some fast, mad, wild music everyone will shoot around the room like idiots crashing into each other.   

I think this is the best explanation yet for solids liquids or gases - all Anastasia has to answer is that solids are really snogging molecules. ;D

(incidentally, I don't dance, so maybe I am not matter at all).
 

Offline Make it Lady

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What are the rules for solids, liquids and gases?
« Reply #21 on: 05/03/2008 23:03:34 »
Light arrow I refer you to the first half of my statement and another someone "I dance therefore I am!"
Anastasia, have you done the homework now? Teachers don't usually give you that long these days before you have to hand it in, so I'd like to know what mark/comment we all got from Miss/Sir.

 

Offline Nandini Sree

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Re: What are the rules for solids, liquids and gases?
« Reply #22 on: 28/06/2016 07:34:39 »
I have checked in websites for rules of three matters

solid state

Solids always take up the same amount of space. They do not spread out like gases.

liquid
Even when liquids change their shape, they always take up the same amount of space. Their volume stays the same.

gases
Gases do not keep their shape or always take up the same amount of space. They spread out and change their shape and volume to fill up whatever container they are in.

finally, I found an interesting Density of solids app i found how to measure
Density of various solids using liquids, In addition it has a quiz at the end to make your learning exciting. here is the app ajax.densityofsolids
 

Offline IAMREALITY

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Re: What are the rules for solids, liquids and gases?
« Reply #23 on: 28/06/2016 20:46:55 »
I have checked in websites for rules of three matters

solid state

Solids always take up the same amount of space. They do not spread out like gases.

liquid
Even when liquids change their shape, they always take up the same amount of space. Their volume stays the same.

gases
Gases do not keep their shape or always take up the same amount of space. They spread out and change their shape and volume to fill up whatever container they are in.

finally, I found an interesting Density of solids app i found how to measure
Density of various solids using liquids, In addition it has a quiz at the end to make your learning exciting. here is the app ajax.densityofsolids

Based on the student's question, I'd assume this to be the most logical and correct answer.

It's amazing how far some could take the debate of a 4th grader's science homework though lol.
 

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Re: What are the rules for solids, liquids and gases?
« Reply #23 on: 28/06/2016 20:46:55 »

 

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