Covalent Bonding Flashcards
(18 cards)
What is a covalent bond?
The strong electro static forces of attraction between the shared pair of electron and the positive nuclei.
What are covalent bonds between?
Non - Metal Elements
What are simple molecular structures?
Simple molecular structures have covalent bonds joining the atoms together, but intermolecular forces that act between neighbouring molecules are weak.
Why do simple molecular structures have low melting and boiling points?
- There are weak intermolecular forces between the molecules
- These forces require little energy to overcome
Why are simple molecular structures bad conductors of electricity?
There are no free ions or electrons to move and carry the charge.
How does increasing relative molecular mass affect melting and boiling points?
As relative molecular mass increases, melting and boiling points rise because more electrons mean stronger intermolecular forces, requiring more heat energy to overcome them.
What are fullerenes?
Fullerenes are a group of carbon allotropes made up of molecules that form hollow tubes or spheres.
What structure is C 60 Fullerene?
C60 is a simple molecular structure.
Why can C60 fullerene not conduct electricity?
- Although the fourth electron in C60 is not bonded, the electrons are only freely moving within the buckyballs and cannot migrate from one buckyball to another, so C60 does not conduct electricity
Why does C60 fullerene have a low melting point?
- C60 fullerene is a simple molecular structure
- There are weak intermolecular forces between individual buckyballs
- Little energy is needed to overcome these forces
What are the uses of C60 fullerene?
- Targeted drug delivery
- Catalysts (trap catalyst molecules on their surface)
- Industrial lubricants
Why do giant covalent structures have high melting and boiling points?
- There are strong covalent bonds between atoms
- These require lots of energy to overcome
Why is diamond hard?
- Each carbon atom is covalently bonded to four other carbon atoms (tetra hedonal structure)
- The covalent bonds are very strong
Why does diamond have a high melting and boiling point?
- It has a giant covalent structure
- There are strong covalent bonds between atoms
- Which require lots of energy to break
Uses of Diamond
- Jewelry
- Drilling
- Cutting
- Engraving
- Cutting edges in scalpel
Why is graphite soft and slippery?
- Each carbon atom is bonded to three other carbon atom forming layers
- The layers are free to slide over each other because there are only weak intermolecular forces between the layers, not covalent bonds
Why can graphite conduct electricity and heat?
- Due to each carbon atom only forming three bonds, one electron from each carbon atom is delocalised
- The delocalised electrons are free to move through its structure.
Why does graphite have a high melting and boiling point?
- It has a giant covalent structure
- There are strong covalent bonds between atoms which require lots of energy to break
