CH 8: Kinetic Particle Model of Matter

• The kinetic model of matter states that all matter is made up of tiny particles called atoms or molecules in continuous random motion.
• Common states of matter include solid, liquid, and gas.
• For solids, the arrangement of particles is closely packed and in a regular pattern.
• For liquids, the particles are loosely packed and there is some space for movement.
• For gases, the particles are far apart and there is a large amount of space for movement.
• The shape of a solid is fixed, the particles are held in a fixed shape by strong intermolecular attractive force.
• The shape of a liquid takes the shape of the container it occupies, the particles can move about relatively freely compared to a solid.
• The volume of a solid is fixed at constant temperature, the particles are closely packed in a regular pattern.
• The density of a solid is high, the particles are closely packed in a regular pattern.
• The compressibility of a solid is incompressible because it has very little space between particles.
• The volume of a liquid has a fixed volume at constant temperature, the particles can move about freely and randomly.
• The density of a liquid is relatively medium, there is some space between particles.
• When the volume of gas is constant, the overall constant capital k equals p over v over t, and k over v equals to p over t.
• Gas particles gain more energy when temperature increases, hence they move faster and the frequency of collision between gas particles and the wall of container increases.
• When the volume of gas is decreased or the gas is compressed, the space between gas particles reduces or the number of gas particles per unit volume increases, resulting in an increase in pressure.
• Pressure of gas is defined as the force exerted by the gas on the wall of the container, divided by the area of the wall.
• The ideal gas formula is: k equals pv over t, where k is a constant, v is the volume of gas, and t is the temperature of gas.
• In constant volume, pressure of gas is directly proportional to the temperature, as represented by a straight line on a graph.
• When gas is heated, temperature increases and gas particles gain more energy, causing the volume to increase and the number of gas particles per unit volume to decrease, resulting in no change in pressure.
• When the temperature of gas is constant, the overall constant capital k equals pv and therefore p equals k over v, indicating that pressure of gas is inversely proportional to the volume.
• The compressibility of a liquid is incompressible because it has very little space between particles.
• The shape of a gas takes the shape of the container it occupies, the particles can move about freely and randomly.
• The volume of a gas takes the volume of the container it occupies, the particles can move about freely and randomly.
• The density of a gas is relatively low, the particles are far apart and there is a large amount of space for movement.
• The compressibility of a gas is compressible because there is a lot of space between particles.
• In a brownian motion experiment, a glass cell with a lid is used to trap smoke particles, which are observed to move in a zigzag manner due to the random motion of air molecules.
• If temperature increases, the speed of air molecules increases, causing smoke particles to move about more rapidly.
• Gas particles are constantly in motion, colliding with each other and with the wall of the container.
• The total force exerted on the wall by all the gas particles is observed in a brownian motion experiment.