Structure And Bonding Flashcards
By what force are ionic compounds help together by?
Strong electrostatic forces between oppositely charged ions
What is ionic bonding?
When non metals and metals transfer electrons to become ions
What happens when ions are melted or dissolved?
They conduct electricity due to free movement of ions
What is covalent bonding?
When atoms share electrons
What are the forces between molecules
Weak intermolecular forces because the molecules are easily parted from eachother
Do substances made from simple molecules conduct electricity?
No as they haven’t got an overall electric charge
Give 3 examples of giant covalent structures
Graphite
Diamond
Silicon dioxide
What is another name for giant covalent structures
Macromolecules
Describe the carbon atom structure in a diamond
Each carbon atom forms 4 covalent bonds in a very rigid and hard structure so diamond is very hard
Describe the carbon atom structure in graphite
Each carbon atom bonds to 3 others forming layers. These layers are free to slide over eachother because there are no covalent bonds between the layers, and they have weak intermolecular forces
Why do metals conduct heat and electricity
They have free electrons that can move around the metal
Why can some metals be bend or shaped
The layers of atoms are free to slide over eachother making them malleable
What is an alloy
A mixture of two metals in order to make is stronger, the different size of atoms distort the layers of the metal making it hard for atoms to slide over each other
Describe thermosoftening polymers
Individually tangled chains of polymers held together by weak intermolecular forces
Describe thermosetting polymers
Have strong intermolecular forces between the polymer chains, called cross links that hold the chains firmly together
