C1.1 The Particle Model

Question 1

Solid

Answer 1

A state of matter where particles are closely packed in fixed positions, vibrating in place.

Question 2

Liquid

Answer 2

A state of matter where particles are close together but can move past each other, allowing the substance to flow.

Question 3

Gas

Answer 3

A state of matter where particles are far apart and move freely in all directions.

Question 4

Melting

Answer 4

The process where a solid absorbs heat and turns into a liquid as particles gain enough energy to move past each other.

Question 5

Freezing

Answer 5

The process where a liquid loses heat, causing its particles to slow down and arrange into a fixed structure, forming a solid.

Question 6

Evaporation

Answer 6

The process where particles on the surface of a liquid gain enough energy to escape as a gas, typically occurring below the boiling point.

Question 7

Boiling

Answer 7

A rapid state change from liquid to gas throughout the liquid, occurring when the liquid reaches its boiling point.

Question 8

Condensation

Answer 8

The process where gas particles lose energy and move closer together to form a liquid.

Question 9

Sublimation

Answer 9

A direct change from solid to gas without passing through the liquid state, as particles gain sufficient energy to break free from the solid structure.

Question 10

Deposition

Answer 10

The reverse of sublimation, where a gas changes directly into a solid without becoming a liquid first, as particles lose energy rapidly.

Question 11

Diffusion

Answer 11

The movement of particles from an area of high concentration to an area of low concentration.

Question 12

Particle Model

Answer 12

A scientific model that explains the arrangement and movement of particles in solids, liquids, and gases.

Question 13

forces

Limitation 1

Answer 13

The model doesn’t show the forces of attraction between particles.

Question 14

shape

Limitation 2

Answer 14

The model assumes particles are uniform spheres and doesn’t represent their actual size or shape.

Question 15

movement

Limitation 3

Answer 15

It simplifies the movement of particles, not accounting for the variety of speeds in real gases or liquids.

Question 16

shape

Limitation 4

Answer 16

The particle model is often shown in two dimensions, but particles are arranged in three dimensions.

Question 17

Physical changes

Answer 17

Changes that affect the arrangement of particles of the substance. No new substances are made.

Question 18

Chemical changes

Answer 18

Changes that affect the composition of the substance(s) involved.