The main differences in solids, liquids and gases is:
how close their particles are,
the speed of the particles &
type of motion
B. kinetic molecular theory – particles of matter are in constant motion & the speed of the particles increases w/ increased temp
1. In solids, the particles are very close together, touching each other and packed tightly enough that the particles cannot move at all except to rotate on their axes & vibrate.
a. SOLIDS - have definite shape and definite volume
*usually HIGH density
*expands only slightly when heated
* almost incompressible because particles are packed very close together.
Crystalline - repeating geometric pattern
Amorphous - no geometric pattern
Types of Solids Ionic (NaCl) Metallic
2. In liquids , the particles touch each other constantly but can slide past each other as the liquid FLOWS.
a. LIQUIDS –
*have definite volume but not definite shape
*usually SLIGHTLY less dense than solids
*expand more than solids when heated
*takes the shape of its container
*flows – viscosity refers to how quickly or slowly a fluid flows or changes
B. Liquid Properties
attractive force between particles in a liquid that minimizes surface area
attractive force between the surface of a liquid and the surface of a solid – paper towels!
3. In gases , the particles are completely independent and do not touch each other continually.
b. GASES - have no definite shape & no definite volume
*very LOW density
*expand greatly when heated
*take the shape of the container
*particles are completely independent and do not touch each other except
when they bump into each other.
4. phase changes
a. melting/freezing – solid to liquid & liquid to solid
b. boiling/condensating—liquid to gas gas to liquid
c. sublimation/deposition—solid to gas & gas to solid
Liquids vs. Solids
Stronger than in gases
slower than in gases
IMF Strength Fluid Density Compressible Diffusion
of attraction between
Bonds exist within
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 442
Water is an exception to the rule! Water becomes more dense as it gets colder UNTIL it reaches 4 C – it is MOST dense at 4 C. As it gets colder (3 C & lower) it expands & so gets less dense. That is why ice floats in water!