Metallic bonding Flashcards
What are the properties of metals?
Conduct electricity, conduct heat, lustrous, high melting points, dense, malleable, hard, high tensile strength, reductants.
How do metals conducts heat?
The heat causes the delocalised electrons to gain energy which makes them move faster and collide more frequently, allowing them to transfer the heat to other electrons.
Why are metals lustrous?
Metals contain delocalised electrons which reflect the light from metals this gives the metals a shiny appearance.
Why are metals dense?
Metals have high densities because the particles in the metallic lattice are tightly packed together.
Why do metals have high melting points and are hard?
Metals are held together by strong metallic bonds from the electrostatic attraction between the cations and the delocalised electrons.
Why are metals good conductors of electricity?
Metals contain negatively charged electrons that are free to move. Therefore they can carry a charge through a metal.
When an electric field is applied the electrons will move to the positive and therefore create an electric current.
Why are metals malleable and ductile?
Metals are bonded together by electrostatic forces which are non directional, this means atoms may slide over each other with out disrupting the attraction.
What are the limitations to the metallic bonding model?
The model does not allow for any exceptions and does not explain them. Eg. mercury liquid at room temp, differences in melting temps and magnetic properties.
What is an alloy?
An alloy is a metal that has been combined with another metal or sometimes non metal, resulting in a change of properties that will better suit the metals use.
What are the different types of alloys?
Substitutional: one atom is subbed for a another atom of the same size. Layers of lattice cannot easily move, alloy is less malleable and harder than pure metal.
Interstitial: Smaller atoms fit between gaps in the pure metals lattice. layers of the lattice can’t move easily so alloy is less malleable.
What are some benefits of alloying?
Usually depends on the type of alloy created.
- improved strength
- resistance to corrosion
- less malleable
- reduced melting temp
Alloying: True of False
- Pure metals will be more malleable than alloy
- The alloy will be more resistant to corrosion than pure metal
- Pure metal will have higher electrical conductivity than alloy
- Alloy will usually have higher meting temp than the two pure metals
- True: alloys are less malleab
- True: alloys have improved benefits
- True: alloys have improved benefits
- False: alloys have lower melting points because their bond are weakened by the interruption of another element
Alloying: True or False
- Crystals of one metal will be distributed throughout the crystals of the other metal
- Small atoms may fit into the lattice spaces between cations of the metallic lattice
- Metal ions of one kind may replace other metal ions in the lattice
- An alloy produces a compound with a distinct formula
- True
- True: interstitial
- True: substitutional
- False: There is no certain amount of metals that need to be added to each other to create an alloy. You can use as much or as little as you want to create an alloy
The bonding in metals is beast explained as attraction between…?
Positive ions and in a sea of electrons.
What are some properties of s block metals?
Form compounds that are usually white.
- Alkali metals are very reactive, low density, lowish melting point, large atomic radius
- Alkaline Earth metals are reactive (less than alkali), harder, higher melting points