1. Gold 24 karat gold 18 karat gold 14 karat gold 24/24 atoms Au
Copper
Silver
24 karat gold karat gold karat gold
Pure gold (24 karat) is too soft (malleable) for use in jewelry. An alloy is made with copper or silver to make the gold harder and more durable. 14 karat gold means if you take 24 atoms out of the sample 14 will be gold atoms and the remaining 10 atoms another metal.
Many years ago, coins were made from pure silver and pure gold. Dishonest people would shave off the edges of the coins to steal a small amount of silver or gold. Ridges were added to coins to stop people from shaving the coins.
Emphasize that alloys are solutions or mixtures of metals. An alloy’s characteristics differ from those of the metals that compose it.
How are the silver atoms arranged in the14-karat gold?
(They are evenly dispersed among the gold atoms.)
If you were to melt the ring, how would the silver atoms be arranged in the solution?
(They would be evenly dispersed.)
Can an alloy be composed of more than two different metals?
(yes)
24/24 atoms Au
18/24 atoms Au
14/24 atoms Au

2. An alloy is a mixture of metals.
Brass = Copper + Zinc
Solid brass
homogeneous mixture
a substitutional alloy
Solid Brass
Consumer Tip
Pay attention to labels when purchasing brass. Brass is sold with the label ‘Brass’ or ‘Solid Brass’.
‘Brass’ means brass coated – the object is not ‘solid brass’. It is likely inexpensive, cheap zinc in the center and has only a thin coating of brass on the outside.
Toilet bowl seat screws are often sold as ‘brass’ ($1.29) or ‘solid brass’ ($1.99).
Pay more, the ‘brass’ screw may snap off as zinc is a brittle metal under stress.
‘Solid brass’ is stronger and the better value.
Copper
Zinc

3. Brass Plated Brass = Copper + Zinc Brass plated heterogeneous mixture
Only brass on outside
Brass Plated
Copper
Zinc

4. Hardened Steel Steel Iron Carbon a interstitial alloy
Carbon is added to steel to make it harder. The addition of too much carbon makes steel very strong, but brittle. A bridge made this way would not sag when stressed, but would snap when too much pressure was applied. Engineers figure the optimal amount of carbon to add to make steel strong, but not too brittle.
Look for link: Steel
Steel
Iron
Carbon

5. Steel Alloys Stainless steel Tungsten hardened steel Vanadium steel
Tensile strength
Force is added
Stainless steel
Tungsten hardened steel
Vanadium steel
We can engineer properties
Add carbon to increase strength
Too much carbon  too brittle and snaps
Too little carbon  too ductile and iron bends
Look for links:

6. Galvanized Nails and Screws
Zinc coating prevents rust
Use deck screws for any outdoor project
Iron will rust if untreated
Weaken and break
Galvanized means to be coated with zinc.
The Tin Man – Wizard Of Oz (1939)

7. Nitinol Wire Alloy of nickel and titanium Remembers shape when heated
Applications:
surgery, shirts that do not need to be ironed.
Link to show video of nitonel wire performing.
Add reference to ChemMatters article on nitonel wire
Nitinol (pronounced “night-in-all”) is a generic trade name for NiTi alloys, which stands for Nickel (Ni), Titanium (Ti) and the US Naval Ordinance Laboratory (NOL) where the alloy was discovered in the early 1960s by William Beuhler.
Nitinol's physical function resembles Biological Muscle: when activated it contracts - an effect opposite to that of standard metals that expand when heated.  To activate Nitinol it is heated above its transition temperature (typically 70°C). When the material cools it can be stretched back it its original shape.
But it also has a Shape Memory Effect (SME): It can be made to remember a particular shape. Once the memory is established, it can be bent out of shape. Heating the alloy above its transition temperature will return it to its memorized shape. You can modify the "memory" shape of the wire supplied by annealing the wire. 

8. Properties of Matter Electrical Conductivity Heat Conductivity Density
Melting Point
Boiling Point
Malleability
Ductility