C1.1 The Particle Model Flashcards
What are particles?
A tiny bit of matter such as atoms, molecules or ions
What is the arrangement of solids liquids and gases
Tightly packed, regular
Packed, randomly arranged but touching
Far apart, random
What is the relative distance between solids liquids and gases
Very close
Close
Very far apart
Movement of solids liquids and gases particles
Vibrate of the spot
Flow around each other
Randomly moves in different directions quickly
Why can’t a solid be compressed?
There is no space for particles to move into since they are tightly packed
Why can’t a solid flow?
The atoms are tightly packed in a fixed shape so they can’t move around each other.
What is a chemical change?
List some examples
A change where the atoms rearrange and rebond to produce one or more new substances with very different properties. They are often difficult to reverse
Examples: combustion, oxidation
What is a physical change?
List some examples
A change where no new substance is made. The particles only rearrange and it is reversible
Examples: state change, diffusion, chromatography
What is the difference particle wise between chemical and physical changes?
In a physical change the particles stay the same but they rearrange. Eg when an ice cube melts, the particles are rearranged randomly
In a chemical change the bonds break and reform in different ways
Ratio of distance to diameter
= distance between atoms/ diameter of an atom
Advantages of the particle model are:
Simple and easy to draw and understand
Easy to identify properties
Bonding can be seen
Different atoms can be differentiated
Limitations of the particle model
The space between particles Forces between particles Size of particles Shapes of particles Movement of particles
What is an atom?
The smallest particle of an element that still has its chemical properties. Different elements have different atoms
What is a molecule
2 or more atoms bonded together
What is bond length?
The distance between the centres of 2 different bonded atoms
