1. Thr Particulate Nature Of Matter Flashcards
Describe the arrangement and movement of particles in solids
Tightly packed together in a regular arrangement
Vibrate in fixed position
Describe the arrangement and movement of particles in liquids
Closely packed together but able to move past each other
Vibrate and move around each other
Describe the arrangement and movement of particles in gases
Well separated in a random arrangement
Vibrate and move freely at high speeds
Compare the relative energies of particles in solids, liquids and gases
Particles in a solid have the least amount of energy and particles in a gas have the most energy
What are the names for the state changes from solid to liquid and vice versa
Solid —> liquid - melting
Liquid —> solid - freezing
What are the names for the state changes from liquid to gas and vice versa
Liquid —> gas - evaporation
Gas —> liquid - condensation
What is the term describing when a solid changes straight into a gas
Sublimation
Describe the forces between particles in solids, liquids and gases
Solids - strong force of attraction between particles which keep them in fixed positions
Liquid - weaker attractive forces than in solids
Gases - no intermolecular forces so particles move randomly
Use kinetic theory to describe what happens when a solid melts
Particles in the solid absorb thermal energy when heated and convert into kinetic energy
This causes the particles to vibrate more
The solid then expands until the structure breaks, and it becomes a liquid
Use kinetic theory to describe what happens when a liquid freezes
When cooled, the liquid particles slow down
Eventually, the particles move slow enough for forces to hold the particles in a regular solid structure
Use kinetic theory to describe what happens when a liquid evaporates
Particles near the surface of the liquid gain sufficient energy from the surroundings to overcome the forces between molecules and evaporate
Use kinetic theory to describe what happens when a liquid boils
When heated, the particles gain energy and will eventually move fast enough to overcome the forces between them
Use kinetic theory to describe what happens when a gas condense
When cooled, the gas particles slowdown and get closer together
Eventually the forces between the particles will be great enough for the substance to become a liquid
Use kinetic theory to describe what happens during sublimation
Particles on the surface of a solid gain sufficient energy to overcome all forces between them and become a gas
This similar to evaporation but occurs with solids rather than liquids
Substance A melts at -183 C and boils at -50. What state is A at -90 C
Liquid
How does pressure affect the motion of gas particles
As pressure increases, the motion of the particles increases
How does temperature affect the motion of gas particles
As temperature increases, pressure and the kinetic energy of the particles increases which causes the particles to move more
Fluids are what state of matter
Liquid or gas
True or false
Particles in fluids move randomly
TRUE
Explain Brownian motion
Particles in a fluid move randomly because they are bombarded by other randomly moving particles in the fluid
What is evidence for the kinetic particle model of matter
The random motion of particles in a suspension
Explain the process of diffusion
The net movement of particles from an area of high concentration to an area of low concentration
Diffusion is a process that requires no energy
Which states of matter does diffusion occur in
Liquids and gases
How does the diffusion rate depend on molecular mass
Particles with a smaller molecular mass have a higher average speed
The rate of diffusion is quicker for molecules with a smaller molecular mass as they can move to different regions faster
