Transcript Document

Solids
Chemistry
Mrs. Coyle
Solids
Atoms vibrate about fixed positions.
Properties of Solids
• Depend on their arrangement of their
atoms.
Melting Points
• Temperature at which a solid changes to a
liquid.
• Vibrations of particles are strong enough
to overcome the attraction that holds them
in fixed locations.
• Melting point is same as freezing points.
Melting Points of Ionic and
Molecular Solids
• Ionic Solids have high melting points
because strong forces are holding the
particles together.
• Molecular Solids have lower melting
points.
• Not all solids melt (ex. Wood, cane sugar,
some plastics)
Most Solids are Crystalline
• Unit cell : the smallest group of particles
that retains the shape of the crystal.
• Crystal Lattice: a repeating array of unit
cells.
Simple Cubic,Body-Centered and
Face-Centered
Allotropes
• Two or more different molecular forms of
the same element in the same physical
state.
Allotropes of Carbon
• Diamond
• Graphite
• Bucky
Balls
Buckminsterfullerene “Bucky Ball”
Amorphous Solids
• No order internal structure
• Examples: glass, plastics, asphalt