The particle model - essential knowledge quiz

Describe the arrangement and movement of particles in a solid.

Arrangement: particles touching, in a fixed position, held together by strong forces of attraction.

Movement: vibrate around in a fixed position.

State three properties of solids.

Hugh density, fixed volume, fixed shape.

Describe the arrangement and movement of particles in a liquid.

Arrangement: particles are touching, forces of attraction are weaker than in a solid.

Movement: free to move randomly around each other.

State three properties of liquids.

Lower density, fixed volume, they can flow.

Describe the arrangement and movement of particles in a gas.

Arrangement: particles are spread out, very weak forces of attraction between the particles.

Movement: move randomly at high speeds.

State three properties of gases.

Low density, no fixed volume or shape, can be compressed, can flow.

Why are changes of state physical changes?

No new substances are produced, and the substance will have the same properties as before if the change is reversed.

What is the equation for calculating density?

Density (kg/m³) = mass (kg) / volume )(m³ )

What is a Eureka can?

A peice of equipment used to measure the volume of an irregularly shaped object. Fill with water just below the spout. Place the object in and measure the volume displaced.

What happens to the particles in a substance if it’s temperature is increased?

They love faster and the energy in their kinetic store increases.

What is the internal energy of a substance?

The total kinetic and potential energy of all the particles im a substance.

What is the name given to the energy transferred when a substance changes state?

Latent heat.

What is the specific latent heat of a substance?

The energy required to change the state of one kilogram of that substance with no temperature change.

What is the specific latent heat of fusion of a substance?

The energy required to change one kilogram of a substance from solid to a liquid at its melting point without changing its temperature.

What is the specific latent heat of vaporisation of a substance?

The energy required to change one kilogram of a substance from liquid to gas at its boiling point without changing its temperature.

What do the flat sections of this graph represent?

B-C = melting / freezing, D-E = evaporation / condensing.

What is the equation to calculate the thermal energy needed for a change in state?

Energy = mass x specific latent heat.

What causes the pressure of gas on a surface?

The force of particles hitting the surface.

Explain why the pressure of a gas in a sealed container increases.

Molecules move faster so they hit the surface with more force and the number of collisions per second increases, so the total force of collisions increases.

What equation links pressure and volume of a gas?

Pressure x volume = constant.

For a constant temperature, describe the relationship between pressure and volume.

Inversely proportional.

Why does decreasing volume increase pressure?

If volume decreases, the particles collide with the walls more frequently. There is more force on the walls and the force per unit area is pressure so pressure increases.