Please enable JavaScript.
Coggle requires JavaScript to display documents.
Year 9 Term 2 (Fluids and states of matter (Changes of state (Substance…
Year 9 Term 2
Fluids and states of matter
The particle model
Solids
Fixed volume and shape
Particles are close together and are held by strong bonds
Liquids
Fixed volume, takes the shape of the container
Particles are close together, are held by fairly strong bonds and can move around
Gases
Expands to fit container and takes the shape of the container
Particles are far apart, are held by very weak forces and can move around
Density
Density is the mass of a volume of something and can be calculated using this formula: density=mass/volume
Possible units are g/cm³ or kg/m³
Changes of state
Substance can change state due to heating or cooling
Website
A liquid evaporates from its surface. When it’s boiling, gas bubbles form within
The melting and freezing points of a substance are at the same temperature. The temperature of a substance does not change during melting, even it is still being heated
Changing state temperature chart
Changing density
Substances expand during heating, because the particles in a solid vibrate more and therefore occupy a larger amount of space. in liquids and gases, the particles move faster and take up more space
If a substance expands, its density goes down, as there are the same amount of particles but more space for them to fill
Substances contract whilst cooling because the particles have less energy so don’t move as much. This reduces the volume and therefore increases the density. When a liquid freezes and solidifies, it’s density greatly increases.
Ice is an anomaly, as it is less dense than water, which is why it floats
Pressure in fluids
Gases and liquids are considered to be fluids, meaning that they can flow. Pressure in fluids acts in all directions at once.
The particles in fluids are always moving and hitting the walls of their container or anything else that they make contact with. The force of these collisions cause pressure
Floating and sinking
Drag
Force fields and electromagnets
Magnets
