C1.1 - The Particle Model Flashcards
What does the particle model describe?
The particle model describes how particles are arranged and how they move in solids, liquids, and gases.
Describe solids.
- Very close together
- Regular arrangement
- Vibrate about fixed positions
Describe liquids.
- Close.
- Random arrangement.
- Move around each other.
Describe gases.
- Far apart.
- Random arrangement.
- Move quickly in all directions.
What does the particle model explain?
The particle model explains why some of the properties of a substance depend on its state.
Why can’t you compress solids and liquids?
There are no space for the particles to move into.
Why can’t a solid flow?
A solid has a fixed shape and its particles vibrate about fixed positions which means they cannot move from place to place and hence cannot flow.
What are the properties of a physical change?
- Happens when a substance changes state or
shape. - Many can be reversed.
- No new substances are made.
What are the properties of a chemical change?
- Produces one or more new substances.
- Properties of the new substances are often very
different from the properties of the original
substances. - Many are difficult or impossible to reverse.
What happens when a substance changes state?
The particles of the substance stay the same but their arrangement and movement changes.
What happens to the particles in a chemical change?
Particles break up and then join together in different ways which makes new substances.
How do you calculate the ratio of distance to diameter between to atoms?
Ratio of distance to diameter = Distance between atoms/Diameter of atoms
What are the attractive forces between particles called?
Electrostatic forces of attraction between positive and negative charges.
What are the three main limitations of the particle model?
- The forces between particles.
- The size of particles.
- The space between the particles.
