Structure And Bonding Flashcards
Describe and explain the melting and boiling points of ions
The melting and boiling points are high, due to the strong intermolecular forces. The greater the charge on an ion, the higher the melting and boiling points will be.
Do ions conduct electricity?
Yes, when as a liquid or dissolved. This is because of the free ions.
How are ionic compounds held together?
They are held together by an ionic lattice, with an atom of one type not touching any others of it’s type. The lattice is held together by the attraction.
How are ionic bonds formed?
One atom(metal) gives electrons to another atom(non-metal), so they both gain a full outer shell, and become charged ions.
How does covalent bonding work?
It is between non metals, and they share their electrons, to both gain a full outer shell. There can be multiple shares per atom.
Describe the forces in a covalent bond
In a covalent bond there are strong covalent bonds, but weak intermolecular forces.
Describe and explain the melting and boiling points in a simple covalent molecule
They low melting and boiling points, due to the weak intermolecular forces.
Describe how diamond is formed
It is made of carbon atoms joined together by four strong covalent bonds each.
Describe the properties of diamond
It is very hard, due to the many strong covalent bonds. It is also an electrical insulator, as it has no delocalised electrons.
Describe the uses of diamond, referring to it’s properties and structure
Jewellery-> shiny-> structure has a surface that reflects light
Saws-> hard-> many strong covalent bonds
Electrical insulator-> no delocalised electrons-> four covalent bonds per atom
Describe how graphite is formed
There are three covalent bonds per carbon atom, leaving one delocalised electron. The gap between the layers of atoms is big, so there are weak intermolecular forces.
Describe and explain the properties of graphite
Graphite conducts electricity, as it has a spare delocalised electron. The layers can slide over each other, as there are weak intermolecular forces.
Describe the uses of graphite. Reference the properties and structure.
Pencils-> layers slide over each other-> weak intermolecular forces, layers fall off
Electrodes-> conducts electricity-> spare delocalised electron, as only three bonds per atom
Lubricants for machines-> layers slide over each other-> weak forces between layers.
How does metallic bonding work?
This is formed when metals are melted. They lose their outer electrons to get a full outer shell. These electrons join a sea of delocalised electrons.
How are the metals held together?
They are held together by the strong attraction between the electrons and ions. The more electrons lost, the greater the attraction, so the metal is stronger.
