particle theory

what is particle theory?

an explanation as to how matter changes state depending on the energy and forces present in the particles in the substance

what would the energy to change from a solid to a liquid be dependant on?

the ‘relative strength’ of the FORCES acting between the particles. stronger the forces, the higher the energy required

so according to particle theory, what happens to a heated solid?

• absorbs thermal energy, converted into kinetic energy

• particles vibrate and expand more, and the temperature increases.

• the solid expands due to the vibrations and the bonds break and melt

• the substance expands more and more as it gains sufficient energy to overcome the IMFs and then evaporate

what are the limitations of particle theory?

• all particles are said to be small, solid and inelastic

• doesn’t consider the difference of effect of atoms, ions, molecules, mixtures etc.

• doesn’t consider intermolecular forces that exist between different particles in different substances