2 Materials And Their Atomic Bonds

Front 1

metals

Back 1

held together by metallic bonds
few have pure metallic bonds
most are prodominately metallic but also show some covalent or ionic tendency.

example Gold

bend bur still strong
atoms pushed together or pulled apart or slide.

orthodontic wires: atoms slide

Front 2

Ceramics

Back 2

bonded with ionic bond
example: salt (sodium chloride)
strong but brittle
Dentistry: rage of colors used : Crowns, translucent : light gives natural appearance.
Glass: term for amorphous or noncrystalline ceramic material.
cerise are strong when compressed b/c atoms are forced together but weak and brittle when pulled or bent.

Front 3

Polymers or Plastics

Back 3

long chains of covalently bonded repeating units.
weakest chainn: fluctuating dipole

Front 4

Composites

Back 4

made of two or more different materials
common composite : mixture of polymers and ceramic: fiberglass
each material that makes up a composite is called a phase.
composite is a Team!
dentistry: early days used for esthetic restorative material
today: variety of purposes.

Front 5

Colloids

Back 5

two phase material
mixes of gases, liquids, or solids
not true solutions of one material dissolved in another such as saltwater.
suspension of one material in another such as fog.
Emulsions: type of colloid composed of two liquids that fo not blend together: oil and vinegar
Transformation: from liquid to a gel: Jello/ jellies

Front 6

amorphous

Back 6

Solid
Short range order
Not as stable
Brittle
Flexibly
can see through/reflet light