Metals
What properties do delocalised electrons give metals?
Thermal conductivity, Electrical conductivity
What is the name of the bond between atoms called in this substance?
Ionic bond
What type of atoms are in this substance?
Only non-metals
What is the name of the bond called in this substance?
Covalent bond
Define what a polymer is
A polymer is a long chain made from many repeating monomers.
Define what an Alloy is
A mixture of a metal with one or more other elements to make a material with improved properties for that use.
What type of atoms are in this substance?
Metal and Non-metals
What is the bond called between the atoms in this substance?
Covalent bonds
Give two examples we learned in class for this material type
Graphite and Diamond
What type of bond holds the atoms together within a polymer chain?
Covalent Bond
What is the name of the bond in this type of material and describe its atomic structure
Metallic bond, 3D lattice
Describe the atomic structure of this substance and the strength of the bond
In a solid state it has a 3D lattice with localised electrons and the bond strength is very strong
Why do some molecular substances have low melting points even though they have strong bonds within the molecule?
It is because they have weak intermolecular forces between the molecules
How many valence electrons does Carbon have?
4
A polymer has long chains that are held together by weak intermolecular forces. What would you expect this polymer to be like? Give TWO properties.
Flexible, low melting point, soft, easily shaped.
Describe what density is
Density tells us how tightly packed the particles in a substance are and how many.
Can this substance conduct electricity?
Explain your answer
No if it is in a solid state due to localised electrons. Yes if it is in an aqueous state, as the electrons can now freely move
At room temperature, oxygen is a gas while water is a liquid. Explain why these molecular substances have different physical states.
It is because the bond between oxygen molecules are weaker than the bond between water molecules. Therefore, it takes more energy to break the bond between water molecules
Which substance has weak intermolecular forces and delocalised electrons? Identify two properties that this structure gives the substance.
Graphite - 1. soft, slippery
2. Conducts electricity
Explain why a polymer with stronger forces between its chains would generally have a higher melting point.
Stronger forces require more energy to break the chains. Therefore more heat energy is needed
What about the atomic structure of metals allows them to be malleable?
Metals are malleable because metallic bonding is non-directional. This means the positive metal ions are attracted to the delocalised electrons in all directions,
Explain why some ionic substances are soluble
Because the attractive forces between water molecules and the ions are stronger than the ionic bonds holding the ions together in the 3D lattice.
Water (H₂O) is a polar molecule. Explain why the water molecule is polar.
Polar is because oxygen has a higher electronegativity than Hydrogen. So the electrons are not shared evenly.
Why are covalent network substances generally insoluble in water?
Because they have strong covalent bonds throughout their structure. The water molecules do not have enough attraction to break these strong bonds apart
What about the structure of polymer chains allows some polymers to be flexible?
The long chains can move and slide past each other because the forces between the chains are relatively weak. This allows the polymer to bend and flex