U11 - metallic bonding Flashcards
Def: Metallic bonds
Metal lattice of positive ions, surrounded by a sea of delocalised electrons
Explain the structure of the metal lattices, zinc and sodium
Coulomb forces between the negatively charged electrons attract the positively charged ions in a giant metallic structure.
The electrostatic forces between the positive and negatively charged particles are strong
How many electrons does sodium aluminium and magnesium lose
Sodium - 1 e
Aluminium - 3 e
Magnesium - 2 e
Why does aluminium have a higher melting and boiling point than sodium
Aluminium has the stronger electrostatic forces i.e. +3 and -3, and will therefore have the higher melting and boiling point than sodium that only has +1 and -1 charges holding the particles together
Properties of metals
shiny
malleable
sonorous
good conductor of electricity
good conductor of heat
Def: shiny
he delocalised electrons on the surface reflect light
Def: Malleable
the positive atomic rests occur in layers, the layers are held together
by strong forces and can slide over each other without breaking apart.
The delocalised electrons maintain attraction between the layers of positive ions.
Def: Sonorous
when struck, metals make a ringing sound, because the
vibration is carried through the metal by the delocalised electrons
Why is metals good conductors of electricity
The delocalised electrons are free to move and
therefore carry charge
Why are metals good conductors of heat
The metal ions are closely packed in the ionic lattice (dense)
which allow the ions to bump into each other, transferring energy from one particle to the next.
The delocalised electrons are also able to take the energy and travel through the metal
Why are metals good conductors of heat
The metal ions are closely packed in the ionic lattice (dense)
which allow the ions to bump into each other, transferring energy from one particle to the next.
The delocalised electrons are also able to take the energy and travel through the metal
