C1 - Particles Flashcards
What do chemists mean when they use the term particles?
Atoms, ions or molecules
What is the arrangement of a solid?
regular
what is the arrangement of a liquid?
random
what is the arrangement of a gas?
random
what is the relative distance between solid particles?
very close
what is the relative distance between liquid particles?
close
what is the relative distance between gas particles?
far apart
what is the main movement of solid particles?
they vibrate around fixed positions
what is the main movement of liquid particles?
they move around each other
what is the main movement of gas particles?
they move quickly in all directions
can you compress a substance in its solid state?
no
why can you not compress a solid or liquid substance?
there is no space for the particles to move into
why do substances in a solid state have a fixed shape?
since it’s particles vibrate around fixed particles and cannot move from place to place
Give 3 examples of chemical changes
- cooking eggs
- steel rusting
- wood burning
- acid + alkali
Give 3 examples of physical changes
- freezing juice to make a lolly
- mixing sand with water
- dissolving sugar in water
What happens to a substance when it changes state?
The substance’s particles stay the same but the movement and arrangement changes
What happens to a substance’s particles during a chemical reaction?
Particles break up and join in different ways
new substances are made
What is the smallest particle that makes up a substance?
atoms
What element has the smallest atom?
Helium atoms
what is the equation to calculate the mean distance between atoms?
distance between atoms
————
diameter of atom
What are the forces between particles called?
Electrostatic forces
State three limitations of the particle model
- unable to see the electrostatic forces
- unable to see the size of particles
- unable to the the space between particles
Why does the volume of a substance increase when it melts?
Some of the forces of attraction are overcome and so the particles can move around each other
describe what happens to the particles of a substance in the liquid state as it cools down but remains in the liquid state
- particles transfer energy its surroundings
- the particles slow down
- some some electrostatic bonds form between them