Bonding, Structure and Properties of Matter Flashcards
Describe the forces of attraction between atoms in molecular compounds and between molecules.
Why are covalent bonds strong?
How does this change with the size of the compound?
The atoms are held together by strong covalent bonds (electrostatic attraction between nuclei and shared electrons is strong)
The intermolecular forces between the molecules are weak, but get stronger the larger the molecule.
Describe the intermolecular forces between polymers, in comparison to simple molecular substances
The intermolecular forces are larger, so more energy is needed to break them.
Explain the m.p and b.p of polymers compared to ionic and giant molecular compounds.
The m.p and b.p are lower because the intermolecular forces are still weaker than covalent and ionic bonds.
(giant molecular are held together by covalent bonds)
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What holds giant molecular compounds together?
Strong covalent bonds, therefore they have high melting and boiling points.
How many bonds does each carbon atom make in:
- Diamond
- Graphite
- Four
- Three (each has a delocalised electron)
Describe the structure of graphite
-Each carbon atom is bonded to 3 other carbon atoms. They form layers of hexagonal rings held together by intermolecular forces.
Why can graphite conduct electricity?
Each carbon atom has a delocalised electron which is free to move throughout and within layers and carry electrical charge.
Why can graphite conduct electricity?
Each carbon atom has a delocalised electron which is free to move and carry electrical charge.
What is graphene and describe its properties and uses.
A single layer of graphite (so strong and conducts). It can be used to add strength since its strong and light, as well as in electronics. Without adding much mass.
What is a fullerene and give their uses
Sa:v ratio?
Hollow structures made from carbon atoms. Uses: Catalysts, Lubricants, Drug delivery in the body.
Why do metals have high melting and boiling points?
There is strong electrostatic forces of attraction between the metal ions and the sea of delocalised electrons. Lots of energy is needed to overcome this.
