4th Grading Science

• Kinetic Molecular Theory of Gases


  A model to explain the behavior of constantly moving particles.
• Kinetic Molecular Theory


  • Gases are made up of tiny particles
  • Gas molecules are most likely empty space because of the distances between particles making gases compressible and with low density
  • Gas particles move in straight lines and in rapid directions
  • Gases diffuse very fast. This allows two or more gases to combine readily
  • The forces of attraction between gases are negligible because of the wide spaces between the particles
  • Gas particles collide with the walls of the container, but do not lose their kinetic energy
  • At a given temperature, all gases have the same average kinetic energy
• Characteristics of gases based on kinetic molecular theory

  • Expansion
  • Fluidity
  • Low density
  • Compressibility
• Expansion


  Gases do not have a definite shape or a definite volume. They completely fill any container and take its shape. Gas particles move rapidly in all directions without significant attraction between them.
• Fluidity


  The ability to flow, or move from one place to another. Since there are no attractions between particles, the particles can slide past each other. This is why gases have no definite shape.
• Low density


  The density of a gaseous substance at atmospheric pressure is about 1/1000 the density of the same substance in the liquid or solid state. The reason is that the particles are so much farther apart in the gaseous state.
• Compressibility


  Gases are easily compressed because of the space between their particles. During compression, the gas particles which are very far apart from one another move closer together.
• Boyle's Law


  The pressure and volume of gas are inversely proportional, provided that the temperature remains constant.
• Boyle's Law


  As volume increases, pressure decreases. Also, as volume decreases, pressure increases.
• Charles' Law


  The temperature and volume of gas are directly proportional, provided that the pressure remains constant.
• Charles' Law


  As temperature increases, volume increases. Also, temperature decreases, volume decreases.
• Gay-Lussac's Law


  The temperature and pressure of gas are directly proportional to each other, provided that the volume remains constant.
• Combined Gas Law Formula

  P1V1/T1 = P2V2/T2
• Boyle's Law

  Named after Robert Boyle, states that the pressure and volume of gas are inversely proportional, provided that the temperature remains constant
• Charles Law

  Named after Jacques Charles, states that the temperature and volume of gas are directly proportional, provided that the pressure remains constant.
• Gay-Lussac's Law

  Named after Joseph Louis Gay-Lussac, states that the temperature and pressure of gas are directly proportional to each other, provided that the volume remains constant
• Gay-Lussac's Law Formula

  P1T2=P2T1
• Charles Law Formula

  V1T2=V2T1
• Boyles Law Formula

  P1V1=P2V2
• Kinetic Molecular Theory

  It is applied to perceive and justify the gas laws.
• Kinetic Molecular Theory

  It also states that gas particles are in constant motion and exhibit perfectly elastic collision.