Structures Flashcards
What are ionic substances made up of?
metals and non-metals
What gives giant ionic lattices their shape?
the positive ions and negative ions strongly attract each other to make a regular crystal structure.
what are the properties of a giant ionic lattice?
high melting and boiling don’t
conduct electricity when molten or in an aqueous solution
don’t conduct electricity as a solid
Why do giant ionic lattices have a high melting and boiling point?
a lot of energy need to overcome the strong forces of electrostatic attraction
Why do giant ionic lattices conduct electricity when molten or in an aqueous solution?
because the ions are able to move and can carry the current from one place to another.
Why don’t giant ionic lattices conduct electricity as a solid?
because the ions aren’t able to move
What are the properties of a simple molecular structure?
low melting and boiling point
soft as a solid
doesn’t conduct electricity
Why do simple molecular molecules have a low boiling and melting point?
the molecules only have weak intermolecular forces which are easy to break.
Why can’r simple molecular structures conduct electricity?
because the electrons aren’t free to move as they are in a covalent bond.
What are the properties of a giant molecular lattice?
strong covalent bonds
no weak intermolecular forces
doesn’t conduct electricity as it has no free electrons
high melting and boiling point
Explain the structure and properties of graphite.
each carbon atom is covalently bonded to three others because the fourth outer electron of each carbon atom is delocalised. The delocalised electrons are free to move and conduct electricity.
strong covalent bonds within layers means graphite has a high melting and boiling point
the weak forces between the layers are easily broken so they can slip over each other
Explain the structure and properties of diamond.
each carbon atom is covalently bonded to 4 other carbon atoms
diamond has a very high melting point
extremely hard
it can’t conduct electricity because all the outer electrons are in a covalent bond.
