Diamonds vs. Spider Silk
Crystals and Polymers
Do you remember which
molecules represent a solid?
• The molecules of most solids form regular
shapes through repeating patterns.
Two Types of Solids
Crystals
Polymers
(Diamonds)
(Spider web silk)
Crystalline Solids
1. Crystals (crystalline solids) have
molecules that form a regular,
repeating pattern.
2. These patterns create crystals.
3. In general, crystalline solids do
not get soft when heated.
4. Examples of crystalline solids
are sugar, salt, and diamonds.
The Molecules in Crystalline Solids
Diamonds
Graphite (pencil lead)
1. What do the round structures represent?
2. Why are all the atoms the same color?
3. Which substance is more hard? Why?
Diamond vs. Graphite
What is similar about these substances?
Both diamonds and graphite are made of the
same atoms, carbon; despite having distinct
physical properties.
•What accounts for their different physical
properties (hardness, luster, density, etc)?
Two Models of Salt Molecules
1. What kind of observations can you make about
the molecular structure of salt?
There are 2 different types of atoms arranged in
repeating patterns that can’t change position.
Polymers
1. A polymer is a large, repetitive,
string-like molecule.
2. Most organic structures are
polymers made of Carbon,
Hydrogen, Oxygen, and/or
Nitrogen.
The Molecules in Polymers
What are some
characteristics
of these
structures?
Cotton
Silk
Cotton and Silk
1.What are some similarities between cotton
and silk?
2.Where do all polymers come from?
Polymers come from organic (living or onceliving) things like plants, petroleum, and animals.