C1 - The Particulate Nature Of Matter

Front 1

State the distinguishing properties of solids, liquids and gases

Back 1

• Particles have a fixed arrangement and position, are very close to each other and can only vibrate

• The particles are arranged randomly, yet are still connected. They can slide past each other and are still close.
  

• The particles have a random arrangement, can more freely, and are spaced out and far apart from each other.
  

Front 2

Describe changes of state:

• Melting
• Boiling
• Evaporating
• Freezing
• Condensation
• Sublimation

Back 2

• solid - liquid
• liquid - gas, above boiling point, affects all particles
• liquid - gas, beneath boiling point, only affects those particles with enough energy
• liquid - solid
• gas - liquid
• solid - gas (directly, without melting then boiling)

Front 3

Explain changes of state in terms of the kinetic theory

Back 3

Constant increase in energy and thus and increasing weakening of bonds and attractions between particles.

Solid heating - solid melting - liquid heating - liquid vaporising - gas heating

Front 4

Describe qualitatively the pressure and temperature of a gas in terms of the motion of its particles

Back 4

The higher the temperature of a gas, the energy the particles have (on average). Therefore, they move faster and more and exert a greater pressure.

Front 5

Show an understanding of the kinetic particle model and Brownian Motion

Back 5

In liquids and gases, the particles are constantly moving and changing direction as they hit other particles. We say that they move in a random way. The idea that particles are constantly in motion is called the kinetic particles theory. It was found that all tiny particles suspended in a fluid show irregular movement. This type of movement is called Brownian Motion and it gives us evidence for the kinetic particle theory.

Front 6

Describe and explain diffusion

Back 6

The random movement of different particles so they get mixed up is called diffusion. Diffusion results in the particles spreading throughout the space available. The overall direction of the movement is from where the particles are more concentrated to there where they are less concentrated.

Front 7

Describe and explain the dependence of the rate of diffusion on molecular mass

Back 7

The speed at which a gas diffuses depends on how heavy its molecules are. Molecules that have a lower mass move faster than those with a higher mass. If the light and heavy molecules have the same amount of energy when they collide, the lighter ones will bounce off the heavier ones quicker, so lighter molecules diffuse faster than heavier molecules.