Metallic bonding Flashcards
What does metallic bonding occur between?
Metal atoms
How does a metallic bond occur?
The outer main levels of the metal atoms merge. The outer electrons no longer associate with a particular atom, which creates a sea of delocalised electrons surrounding positive metal ions.
What does a delocalised electron mean?
It means that it is not belonging to a particular atom
What forces hold the metallic bond together?
The strong electrostatic force of attraction between the positively charged metal ions and the sea of delocalised electrons.
Draw a diagram of a metallic bond
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What kind of structure do metallic bonds form?
Giant metallic crystals
Why are metals good conductors of electricity?
The delocalised electrons are free to move around the giant metallic crystal, carrying the electrical charge as they do so.
Why is it that metals are good conductors of electricity?
This is because the metal ions in the giant crystal are pact tightly together, which enables them to spread heat energy by vibration. In addition the delocalised electrons are free to move about the structure. These electrons carry the thermal energy with them and pass it on to the metal ions (which speeds up the process)
What is the strength of the metallic bond determined by?
The charge on the ion and the size of the ion
Why does the charge of the ion affect the strength of the metallic bond?
This is because the greater the charge of the ion the larger the number of delcocalised electrons which result in stronger electrostatic forces of attraction between the positive metal ions and the delocalised electrons
Why does the size of the ion affect the strength of the metallic bond?
The smaller the ion the closer the delcocalised electrons are to the positive nucleus and so the stronger the bond.
What does malleable mean?
It can be beaten into shape
What does ductile mean?
They can be stretched
Why is it that metals are malleable and ductile?
The giant metallic crystal consists of purely positive metal ions surrounded by a sea of delocalised electrons. Because of this the structure of the crystal remains the same no matter of it is moved (the positive ions do not repel each other unlike ionic bonds)
Why do giant metallic crystals have high boiling points?
Because they have giant structures they have strong electrostatic forces of attraction between the positively charged metal ions and the sea of delocalised electrons throughout. This force of attraction requires a large amount of energy to overcome.
