1 - Kinetic Particle theory Flashcards
Solid state (fixed shape)
- Arrangement of particles
- Attractive forces between particles
- Kinetic energy particles
- Motion of particles
> Closely packed in an orderly manner
Held tgt by v strong forces of attraction
Enough KE to vibrate and rotate about their fixed positions
Cannot move about freely
Why does a solid have a fixed volume?
A solid cannot be compressed/ has a fixed volume since it’s particles are already very close to one another
Liquid state (fixed shape)
- Arrangement of particles
- Attractive forces between particles
- Kinetic energy particles
- Motion of particles
> Arranged in disorderly manner
Weaker forces of attraction than the particles of a solid
More KE than the particle of the same substance in solid state, and are not held in fixed positions
Move freely throughout the liquid
Why does liquid have a fixed volume?
The particles of a liquid are further away from one another than the particles of a solid
HOWEVER
The liquid particles are still packed quite close togerther
THUS
It cannot be compressed and has a fixed volume
Describe gaseous state (no fixed shape)
- Arrangement of particles
- Attractive forces between particles
- Kinetic energy particles
- Motion of particles
> Far apart from one another
Has weaker forces of attraction than particles of a liquid
A lot of KE and are not held in fixed positions
Can move about rapidly and freely
Why does gas not have a fixed shape?
- A lot more space between them compared to the particles of a liquid or solid
- Large space between particles allows the gas to be easily compressed when pressure is applied
- In other words, particles of gas can be forced to move closer tgt
SINCE
A gas can be compressed, it has no fixed volume
(Extra?)
Endothermic vs Exothermic
First one is heat in second one is heat out
Define the process melting
It’s the process by which a substance changes from a solid to a liquid
There are 3 stages to the process of melting, describe the first stage of melting (from solid to liquid)
- Heat energy absorbed by particles of solid
- HE converted to KE
- Particles start to vibrate FASTER about their fixed positions
There are 3 stages to the process of melting, describe the second stage of melting (from solid to liquid)
- When temp high enough, vibrations of particles become sufficient to OVERCOME forces of attraction between them
- Particles begin to break away from fixed positions
[Note: When HE^, KE^] [Overcoming forces of attraction is not considered KE, thus no ^ in HE]
There are 3 stages to the process of melting, describe the third stage of melting (from solid to liquid)
- Particles no longer in fixed positions
- Substance now liquid
- . Particles can move FREELY throughout liquid
Describe the first stage at which particles of a liquid is cooled until it freezes
- Energy is given out by particles of the liquid
2. Particles lose KE and begin to move more slowly
Describe the second stage at which particles of a liquid is cooled until it freezes (mixture of solid and liquid, no temp. change)
- When the temp. is low enough, particles no longer have enough energy to move freely
- Particles start to settle into fixed positions
Describe the third stage at which particles of a liquid is cooled until it freezes
- All particles have settled into fixed positions
- Substance now solid
- Particles can only vibrate about their fixed positions
Define the process of freezing
Process where substance changes from liquid to solid