The Structure of Metals

Chapter 6 Section 4Pg. 176-181

Metallic Bonds

• Metal atoms achieve stable electron configurations by ______ electrons.

• There is a way for metal atoms to lose and gain electrons at the ____ time.– In metals: valence electrons are free to move among

the atoms– In effect: metal atoms become cations surrounded by

a pool of shared electrons• Metallic bond- the __________ between a metal

cation and the shared electrons that surround it

Metallic Bonds

• The _______ in a metal form a lattice that is held in place by strong metallic bonds between the cations and the surrounding valence electrons.

• Although the electrons are ______ among the atoms, the total number of electrons does not change

• Overall, metal is _______

Metallic Bonds

• The ____ valence electrons an atom can contribute to the share pool, the stronger the metallic bonds will be.

• Bonds in alkali metal are relatively _____ because alkali metals contribute only 1 valence electron (reason for being soft, and low melting point)

• __________ metals have more valence electrons to contribute, therefore are harder and have higher melting points

Explaining Properties of Metals

• The ________ of electrons within a metal lattice explains some of the properties of metals.– Ability to conduct electric current and malleability

• Metal has a built-in supply of _______ particles that can flow from one location to another- the pool of electrons– Recall that a flow of charged particles is an electric

current• ________ bonds also explain why metals can be

drawn into thin wires (ductile) without breaking.

Alloys• Alloy- mixture of 2 or more elements, at least

___ of which is a metal• ______ have characteristic properties of

metals• Example: gold jewelry- often mixed with

harder metals (zinc, nickel, silver, etc.) to be more resistant to wear

Alloys• Copper Alloys– 1st important alloy was ______ (associated with

era in history- the Bronze Age)– Bronze contains only copper and tin, which are

relatively soft metals, but when mixed together, the metals are much ______ and stronger than either alone• Bronze is hard, durable, used in statues, propellers

– Scientists can design alloys with specific properties by varying the types and amounts of elements in an _____

Alloys

• Copper Alloys– _____: contains only copper and zinc; softer than

bronze and easier to shape– Brass is also shinier than ______, but likely to

weather more quickly

Alloys

• Steel Alloys– Alloy of ____ that contains carbon– Stainless steel: ________ and very little carbon,

more brittle than other steels that contain more ______

Alloys

• Other Alloys– If a _____ amount of copper or manganese is

added to _________, the result is a stronger material that is still lighter than steel.