P6 - Particles and Matter Flashcards
Describe the structure of a solid according to the Kinetic theory of matter:
The particles are in a fixed shape and vibrate around a fixed position. Therefore, a solid cannot flow and keeps the same volume.
Describe the structure of a liquid according to the Kinetic theory of matter:
The particles in a liquid are close together but not fixed in positon. The particles can move around but stay close together. Therefore, a liquid can flow and takes the shape of a container. A liquid keeps the same volume and cannot be compressed.
Describe the structure of a gas according to the Kinetic theory of matter:
The particles are far apart and move around very fast. As a result of the particles being far apart, gases can be compressed and expanded to fill a container. Gases can flow.
How can you change the physical state of a substance? What are the names of the 6 changes of state?
By heating or cooling the substance.
- Solid to Liquid = Melting
- Liquid to Gas = Vapourising or Boiling
- Gas to Liquid = Condensation
- Liquid to Solid = Freezing/ Solidification
- Solid to Gas = Sublimation
- Gas to Solid = Desublimation
When a substance changes state, why does its mass stay the same?
Because the number of particles stays the same.
What happens to particles in any state when the temperature is increased?
The particles move faster - gain kinetic energy.
Why do the particles of a substance have different energy amounts when it’s in a solid, liquid or gas state?
For a given amount of a substance, its particles will always have more energy in the gas state than in the liquid state, and they have more energy in the liquid state than in the solid state.
What is the temperature at which a solid changes to a liquid called?
Melting point
What is the temperature at which a liquid turns into a gas called?
Boiling point
What is Density?
The amount of mass in a set volume.
What is the equation for Density?
Density = mass / volume
*p=m/v
(g/cm^3)=g/ cm^3 OR kg/cm^3
*p= rho-greek letter for density
What is Archimides’ Principle?
When an object is submerged in a body of water, the volume of the water displaced is the same as the volume of the object displacing it.
What is the aim of RP5 - Density?
To carry out a number of density tests to calculate the density of objects my weighing the object and calculating its volume.
A body of water was used to calculate the volume of irregular shaped objects.
(Archimides’ Principle).
What did you find in terms of the relationship between density and whether an object will sink or float?
An object should float if its density is less than 1g/сm^3.
What happens in terms of tempearture as pure ice is melted?
Its temperature will stay at 0°C until ALL the ice has melted.
What is the rule for a pure substance’s temperature when undergoing a change of state?
For a pure substance undergoing a change of state, its temperature stays the same while the change is taking place.
What is the temperature at which a liquid changes to a solid called?
The Freezing Point
What is the relationship between melting point and freezing point? Why?
They are the same. Because it is the same transition of matter either way.
What is the relationship between boiling point and condensation point? Why?
They are the same. Because it is the same transition of matter either way.