Please enable JavaScript.
Coggle requires JavaScript to display documents.
The Particulate Nature of Matter - Kinetic Theory, The Particulate Nature…
The Particulate Nature of Matter -
Kinetic Theory
Solids
Strong forces of attraction
Atoms vibrate in a fixed position
Fixed volume, shape and high density
Packed closely in a fixed and regular pattern
Liquids
Weaker attractive forces in liquids than in solids
particles close together in an irregular, unfixed pattern
Particles can move and slide past each other
fixed volume but not a fixed shape
moderate to high density
Gases
Little to no inter molecular forces
particles are in random movement
particles are far apart and move quickly and randomly
particles collide with each other to create pressure
No fixed volume or pattern, low density
Basis of the theory
when substances are heated, the particles absorb thermal energy which is converted into kinetic energy
Heating a solid causes its particles to vibrate more
as the temperature increases, they vibrate so much that the solid expands
after the expansion reaches a certain point, the structure breaks and the solid melts
on further heating, some particles at the surface gain sufficient energy to overcome the inter molecular forces and evaporate, and then boil
These changes can be displayed on a heating/cooling curve
The Particulate Nature of Matter -
State Changes
Melting
solid changes into a liquid
heat energy which transforms into kinetic energy
occurs at melting point unique to each pure solid
Boiling
liquid changes into a gas
heat causes bubbles of gas to form below the surface of a liquid, allowing liquid particles to escape from the surface and within the liquid
Occurs at boiling point, unique to each pure liquid
Freezing
liquid changes into a solid
occurs at exactly the same temperature as melting, ; mp and fp are the same
Requires a significant loss of thermal energy
Occurs at temperature unique for each substance
Evaporation
liquid changes into a gas
occurs at the surface of liquids where high energy particles can escape from the liquid’s surface at low temperatures
Occurs below bp
Larger the surface area, the more evaporation occurs
occurs over a range of temperatures
Condensation
gas changes into a liquid, usually on cooling
particles lose energy and group together to form a liquid when they bump into each other because they lack energy to bounce away
No energy required
occurs over a range of temperatures
Sublimation
reverse reaction is called deposition
solid changes directly into a gas
sometimes heat provides enough energy for some particles to overcome the attractive forces and escape into gas form
The Particulate Nature of Matter -
Brownian Motion/Diffusion
Diffusion
process by which different gases or different liquids mix
due to the random motion of particles
particles move from an area of high concentration to an area of low concentration
particles spread out to occupy all of the available space and evens out the concentration
no energy input is required
occurs at a higher rate in higher temperatures and in larger surface areas
Brownian Motion
random movement of particles in a liquid or a gas produced by large numbers of collisions with smaller, often invisible particles
Brownian motion proves the kinetic particle theory
The Particulate Nature of Matter