Bonding Flashcards
(11 cards)
What is a metallic bond and the structure of metals?
2 different structures?
Electrostatic attraction between positive ions and delocalised electrons
Giant metallic Crystal lattice
Hexagonal of cubic close pack structure
What are the melting points and electrical conductivity of metals?
High melting because of strong metallic bonds, lots of energy needed
Solid metals good conductors cause of delocalised electrons carrying charge
Are metals malleable and ductile? Why
All metals are because the layers of ions can slide over each other
What is an ionic bond and what is the structure of ionic substances?
Electrostatic attraction between positive and negative ions
Giant ionic Crystal lattice
What are the melting points and electrical conductivity of ionic structures?
High melting point because lots of energy to break strong ionic bonds
Doesn’t conduct as a solid as negative ions are fixed but can as molten or aqueous as the ions are free
What is the definition of a covalent bond?
Electrostatic attraction between a shared pair of electrons and the nucleus
What elements are involved in either types of covalent structures?
Giant macromolecular - group 4 non metals, carbon and silicon
Simple molecular - non metals
What are the melting points of diamond and graphite?
Very high, strong covalent bonds between atoms which require lots of energy to break
Why doesn’t diamond conduct electricity but graphite does?
All electrons in diamond are in sharper pairs so there are no free delocalised electrons but in graphite for every carbon there is one delocalised electron which can carry charge throughout the structure
What are the melting points of simple molecular structures?
Low as the weak intermolecular forces between molecules require little energy to break
What is the electrical conductivity of simple molecular crystals?
They don’t as all electrons are in shared pairs so there are no delocalised electrons to carry charge throughout the structure
