P3- Particle model of matter

• What are the three states of matter?


  Solids, liquids, and gases
• What are the characteristics of solids?

  • Strong forces of attraction hold particles close together
  • Fixed, regular arrangement of particles
  • Particles vibrate in fixed positions
  • High density
• What are the characteristics of liquids?

  • Weaker forces of attraction than solids
  • Particles are close together but can move past each other
  • Irregular arrangements of particles
  • More energy than solids
  • Move in random directions at low speeds
  • Less dense than solids
• What are the characteristics of gases?

  • Almost no forces of attraction
  • Particles have more energy than in liquids or solids
  • Free to move and travel in random directions at high speeds
  • Low density
• What is the formula for density?

  Density = mass / volume
• How does compressing a material affect its density?


  Compressing a material increases its density by decreasing its volume
• How does density vary with the state of matter?


  • Solid: very dense
  • Liquid: less dense than solids
  • Gas: little density
• What are the steps to find the density of an irregular solid object?


  1. Measure its mass using a balance
  2. Submerge the solid in a eureka can filled with water
  3. Measure the volume of water displaced in the measuring cylinder
  4. Use the formula to find density: Density = mass / volume
• What are the steps to find the density of a liquid?


  1. Place a measuring cylinder on a balance and zero it
  2. Pour 10 ml of the liquid into the measuring cylinder and record its mass
  3. Repeat for additional 10 ml increments until full
  4. Use the formula to find density for each measurement
  5. Calculate the average density for accuracy
• What happens to particles when a system is heated?


  The energy of the particles increases, leading to a change in temperature or state
• What occurs during a change of state?


  A change of state occurs when particles have enough energy to break the bonds holding them together
• What is the conservation of mass principle?


  Mass cannot be created or destroyed; it remains constant during a change of state
• What is the difference between a physical change and a chemical change?


  • Physical change: changes state of matter without altering chemical composition
  • Chemical change: alters the chemical combination of a substance
• What is the process of freezing?


  Freezing is the process where a liquid turns into a solid
• What is the process of melting?


  Melting is the process where a solid turns into a liquid
• What is the process of condensing?


  Condensing is the process where a gas turns into a liquid
• What is the process of evaporating?


  Evaporating is the process where a liquid turns into a gas
• What is the relationship between internal energy and temperature change?


  Internal energy increases with a change in temperature
• What is the significance of internal energy in a system?


  It represents the total energy that particles have in terms of kinetic and potential energy
• What is a chemical change?

  A process where a substance changes its chemical composition.
• What happens to the energy of a substance when it is melting?

  The energy increases as it breaks bonds between particles.
• What occurs to a substance's internal energy when it is condensing or freezing?

  The internal energy decreases as bonds are formed between particles.
• What is latent heat of fusion?

  The energy required to change a substance from solid to liquid at its melting point.
• How does increasing the temperature of a gas affect its particles?

  It increases the kinetic energy and average speed of the particles.
• What is gas pressure?

  Pressure is the force exerted per unit area by gas particles colliding with a surface.
• What happens to gas pressure when the temperature of the gas increases?

  The speed of the particles increases, leading to more collisions and higher pressure.
• What is the relationship between pressure and volume of a gas at constant temperature?

  Pressure and volume are inversely proportional; as one increases, the other decreases.
• What is the equation that describes the relationship between pressure and volume of a gas at constant temperature?

  $PV =$$\text{Constant}$
• What happens to gas pressure when the volume of the gas increases at constant temperature?

  The pressure decreases as the particles spread out and collide with the walls less often.
• How can doing work on a gas increase its temperature?

  Doing work transfers energy to the gas, increasing its internal energy and temperature.
• what is an example of mechanical work being done on a gas?

  By using a bike pump to compress the gas.
• What are the key concepts related to gas behavior under changing conditions?

  • Pressure is force per unit area.
  • Temperature affects particle speed and pressure.
  • Volume changes inversely affect pressure.
  • Work done on gas increases internal energy and temperature.
• What is the formula for density?

  $\rho =$$\frac{m}{V}$
• What units are used for density?

  Kilograms per metre cubed (kg/m³)
• How does density depend on atomic spacing?

  Density depends on the spacing of atoms in matter
• How do the densities of solids and liquids compare?

  Solids and liquids have similar densities
• What is the main exception to the density comparison between solids and liquids?

  Ice has a lower density than water
• Why do gases have a lower density than solids and liquids?

  Gases have increased atomic spacing and energy
• What happens to mass during a change of state?

  Mass is conserved during a change of state
• If 20g of liquid evaporates, how much does the gas weigh?

  20g