the particle model C 1.1 Flashcards
name 3 examples of particles in chemistry
ions, atoms and molecules
describe the main difference between the arrangement of particles in the liquid state and paricles in the gas state
in liquids the particles are random but touching. in gases the particles are random but they are not touching.
explain why you can compress a substance in its gas state
there is space for the particles to move into move into
solid
regular arrangement
very close to each other
vibrate about fixed positions
liquid
random arrangement
close to each other
move around each other
gas
random arrangement
far apart from ecah other
move quickly in all directions
why can you not compress a substance in its solid or liquid state
there is no space for the particles to move into
why can a substance in its solid state not flow
it is in a fixed position and cannot flow. this is because the particles vibrate around fixed positions and cannot move around from place to place
what is a physical change
- when a substance changes shape or breaks
- no new substances are made
- many changes can be reversed eg freezing juice to make ice
what is a chemical change
- produces one or more new substances
- properties of the new one are vey different from those of the original one
- many changes are difficult or impossible to reverse eg cooking eggs
what happens when a substance changes state
the particles stay the same but their arrangements and movement change
what happens in a chemical state
the particles break up and then join together in different ways creating new substances
what is the size of an atom
radius of about 1 x 10 ^-10 or 0.1 nanometers (nm)
electrostatic forces of attraction
show the attraction between positive and negative charges.
the forces become weaker the further apart the particles are. they are strongest in solids and weakest in gases
