C1.1.2 The Particle Model and Density

• What is the particle model used to represent?

  Structure of matter
• In solids, particles are arranged randomly.

  False
• In solids, particles are held together by strong attractive forces
• In liquids, particles experience moderate attractive forces
• How are particles arranged in gases?

  Randomly arranged
• The particle model assumes all matter is made of tiny particles in constant motion
• How do particles in solids move?

  Vibrate in fixed positions
• Particles in liquids are more widely spaced than in gases.

  False
• What type of motion do particles in liquids exhibit?

  Move and slide past each other
• Particles in gases move quickly and randomly.


  True
• In gases, particles are widely spaced
• What is the particle arrangement in solids according to the particle model?

  Regular, ordered lattice
• What is the primary difference in motion between gas and liquid particles?

  Gases move more quickly
• Match the state of matter with its observable property:

  Solid ↔️ Fixed shape

  Liquid ↔️ Ability to flow

  Gas ↔️ Ability to expand
• In liquids, particles move and slide past each other due to moderate attractive forces
• How are the three states of matter explained using the particle model?

  Particle arrangement and motion
• Match the state of matter with its particle motion:

  Solid ↔️ Vibrate in fixed positions

  Liquid ↔️ Move and slide past each other

  Gas ↔️ Move quickly and randomly
• Gases have particles that move quickly and randomly due to weak attractive forces
• What are the three states of matter according to the particle model?

  Solid, liquid, and gas
• In liquids, particles can move and slide past each other.


  True
• Match the state of matter with its particle arrangement and motion:

  Solid ↔️ Regular lattice, vibrate in fixed positions

  Liquid ↔️ Randomly arranged, move and slide past each other

  Gas ↔️ Randomly arranged, move quickly and randomly
• Particles in liquids experience strong attractive forces like those in solids.

  False
• The differences in particle characteristics explain the observable properties
• What are the key characteristics of solids based on the particle model?

  Regular lattice, strong forces
• Particles in gases are widely spaced and experience strong attractive forces.

  False
• In gases, particles move quickly and randomly because they experience weak attractive forces
• What type of forces do particles in solids experience?

  Strong attractive forces
• The strong attractive forces in solids give them a fixed shape.

  True
• In solids, particles are arranged in a regular, ordered lattice
• What is the formula for calculating density?

  $\rho =$$\frac{m}{V}$
• What does the particle model assume about all matter?

  Made of tiny particles
• Why do gases expand to fill their container according to the particle model?

  Weak attractive forces
• Solids generally have a higher density than liquids
• The formula for density is $\rho =$$\frac{m}{V}$, where *m* is the mass and *V* is the volume
• Density is inversely proportional to volume
• The density of water is approximately 1000 kg/m³.
• Match the state of matter with its particle characteristics:

  Solid ↔️ Strong attractive forces

  Liquid ↔️ Moderate attractive forces

  Gas ↔️ Weak attractive forces
• Particles in solids vibrate in fixed positions.


  True
• Gases have widely spaced particles with weak attractive forces.

  True
• Gases have particles that move quickly and randomly.

  True