C1.1 The Particle Model Flashcards
What is a particle?
A tiny bit of matter
What are the 3 states of matter?
Solid
Liquid
Gas
Describe the arrangement of particles in a solid
Particles are packed very close together in a regular arrangement and they vibrate in fixed positions
Describe the arrangement and movement of particles in a liquid
The particles are close together and have a random arrangement. They can move around each other.
Describe the arrangement and movement of particles in a gas
The particles are far apart with a random arrangement. They move quickly in all directions.
Can you compress a substance in solid or liquid state?
No - there is no space for particles to move into
How do the relative energies of particles in a solid, liquid and gas compare?
Particles in a solid have the least energy
Particles in a gas have the most energy
What is a physical change?
A change of state. - Reversible change
Name for Solid to liquid and vice versa
solid to liquid = Melting
Liquid to solid = Freezing
What is a chemical change?
A change that produces one or more new substances. Irreversible change.
Examples of Physical changes:
freezing juice to make ice lolly
Mixing sand with water
dissolving sugar in water
Examples of Chemical changes:
Cooking eggs and food
Steel rusting
Acid reacting with an alkali to form salt and water
What happens when a substance changes state?
Particles stay the same
Arrangement and movement changes
What happens during a chemical change?
Particles break up and join together in different ways
What are the smallest particles called?
Atoms
How big are Helium atoms?
62x10^-12 in diameter
what is the distance between 2 helium atoms?
About 55x larger than diameter - makes it hard to draw gas particles to scale
What forces are between particles?
Electrostatic forces of attraction between pos and neg charges
Do the forces become weaker or stronger if the particles are further apart?
Weaker
The particle model does not take into account…
Forces between particles
Size of particles
Space between particles
What happens to a volume when it melts?
Increases because some of the forces of attraction are overcome and the particles can move around eachother
Volume increases a ____ When a solid becomes a gas, but some forces of attraction remain.
great deal
