6.2 Understanding Physical Change Flashcards
What is the particle model?
A model that shows solid, liquids and gasses
All matter is made up of invisible ball like particles, what are the balls like?
Hard, incompressible and invisible
Attracted to each other
Constantly moving
The bond between solid particles are…
Tight and rigid
Can solids be compressed and so they hold their own shapes?
No they can’t be compressed and they hold their own shape
Do particles in a solid vibrate even though they are in a solid?
Yes they do and vibrations increase with the temperature.
Is a liquid compressible?
No but the particles aren’t stuck as tightly together as a solid so they take the shape of the container.
Do the particles move faster or slower when the temperature is increased?
They move faster
Do the liquid particles vibrate or move freely through a container?
The do both
Is there a large space between the particles in a gas or solid?
In gas, there are large spaces between the particles
Are gasses compressible?
Yes they are highly compressible
How do particles move in gas?
They move in a straight line until colliding with other particles, this is why a gas always fills a container
How do we understand expansion, contraction and pressure?
By looking at how change in motion of particles change with the temperature
What do liquid particles do when they are heated?
The move faster
What do solid particles vibrate in?
The vibrate in a fixed position, as the temperature increases, so does the vibrations. They push the particles further apart, causing the solid to expand
What happens when a solid is cooled?
As the temperature decreases, the particles vibrate less and less, allowing them to be packed more tightly and the solid contracts
Do particles move around faster or slower in liquids than solid?
Faster
What do gas expand to fill?
The container
What happens if the container is flexible when gas particles move faster?
The container increases in size
What happens in the container is rigid when gas particles increase in speed?
The pressure of the container increases
When gas particles cool what to the container?
They travel slower and hit the side of the container less, decreasing the pressure
What happens to solid particles in freezing?
The particles vibrate but are held in position by forces of attraction between them
What happens in melting?
As the temperature increases, so do the vibrations, the solid expands, and so it melts. This is because the vibrations become so energetic that the attraction between particles no longer hold positions.
What is evaporation?
Particles in a liquid escape from surface of liquid to form gas
What happens at the boiling point to the liquid particles?
They move fast until they fly apart and form bubbles in liquid
What is condensation?
Gas particles slow and forces attraction between particles, they can hold and stick together to form liquid droplets.
What is a mixture?
Two or more substances that are mixed together. Mixed particles always form solutions and alloys.
What is a solution?
A mixture
What happens when solute dissolves?
The solvent particles surround the solute particles and carry them away
Are solute particles destroyed?
No they are just spread thinly through the solvent and appear invisible
What can individual solute particles be seen with?
They are so small that they can not be seen with even the most powerful microscope
What is diffusion?
Particles of two gases and two liquids mix evenly without stirring
What travels in a zig-zag in the process of diffusion?
The gas particles
What speeds up diffusion?
A rise in temperature
Why does diffusion in liquids occur less rapidly?
Because the particles are packed closer together
