3.1.3 (b&s) states of matter Flashcards
what are the 3 states of matter?
solid, liquid, gas
properties of solids (4)
- particles remain in fixed positions about which they can only vibrate
- particles are close together and are densely packed
- particles are not free to move about
- forces that hold particles together can be: electrostatic forces of attraction, covalent bonds, metallic bonds, hydrogen bonds, dipole-dipole forces or van der waals forces
properties of liquids (4)
- particles take the shape of their container
- have a fixed volume
- particles free to live randomly around each other
- held together by the forces: van der waals, hydrogen bonding, and dipole-dipole. but feed forces attracting so the particles can change position
properties of gasses (6)
- don’t have a fixed shape
- Will occupy all the volume in its container
- Particles are far apart
- Gases have low density
- Particles move, randomly and rapidly in all directions
- Intermolecular force has no effect unless particles are close together at high pressure or low temperature
what happens to the particles in a solid and its temperature when it’s heated?
The particles gain energy and they vibrate
also the temperature of the solid starts to increase
what is the energy needed to turn a solid into a liquid called?
Enthalpy of fusion
what is the enthalpy of fusion?
The energy needed to turn a solid into a liquid
What happens to the particles wen a liquid is heated?
The particles gain sufficient energy to overcome the forces of attraction between the particles on escape to form a gas
it’s more energy needed to change:
- A solid to a liquid
or
- A liquid to a gas
why?
A liquid to a gas
Because the heat energy is used to break all the forces between particles so that the particles can be completely separated
What is evaporation?
When a liquid changes into a gas without heating
how does evaporation happen?
The most energetic of the particles in a liquid may have sufficient energy to escape from the surface of the liquid move into the gaseous state
what is the energy needed to tell the liquid into a gas called?
the enthalpy of vaporisation
what is the enthalpy of vaporisation?
The energy needed to turn a liquid into a gas
what happens to particles as gases are heated ?
They gain kinetic energy and move much faster
The particles also get further apart and the gas expands considerably
