1How many covalent bonds can carbon form?
4
2What enables the vast array of natural and synthetic organic compounds to occur?
Carbon's ability to form families of similar compounds, chains, and rings
3How many other carbon atoms is each carbon joined to covalently in diamond?
4
4What are the physical properties of diamond?
- Very hard, very high melting point, and does not conduct electricity
- Soft, slippery, low melting point, and conducts electricity
- Soft, high density, and good conductor
- Gaseous, low melting point, and dull
5How many other carbon atoms is each carbon covalently bonded to in graphite?
3
6What shape do the carbon atoms form in layers within graphite?
Hexagonal rings
7Why can layers in graphite slide over each other?
Because there are no covalent bonds between the layers, only weak intermolecular forces
8What makes graphite soft and slippery?
The layers sliding over each other due to weak intermolecular forces
9What is special about one electron from each carbon atom in graphite?
It is delocalised
10Why can graphite conduct electricity unlike diamond?
Because it has delocalised electrons
11What are fullerenes?
Molecules of carbon atoms with hollow shapes based on hexagonal rings
12What was the first fullerene to be discovered?
Buckminsterfullerene (C60)
13What is the shape of Buckminsterfullerene (C60)?
Spherical
14What are carbon nanotubes?
Cylindrical fullerenes with very high length to diameter ratios
15What is graphene?
A single layer of graphite
16During which changes of state is energy transferred TO a compound?
Melting and boiling
17During which changes of state is energy transferred FROM a compound?
Condensing and freezing
18How strong are covalent and ionic bonds?
Very strong
19Why are simple molecules melted or boiled easily?
Because weak intermolecular forces are overcome, not the covalent bonds
20Why do macromolecular substances have very high melting points and are hard to break down?
Because covalent bonds must be overcome
21What is the state of a substance at a temperature below its melting point?
Solid
22What is the state of a substance at a temperature between its melting and boiling points?
Liquid
23What is the state of a substance at a temperature above its boiling point?
Gas
24Why do materials have different properties compared to their bulk chemical form?
Because of their high surface area to volume ratio
25What is the size range of nanoparticles across?
1 to 100 nanometers
26How many atoms do nanoparticles typically contain?
A few hundred atoms
27What are fine particles (PM2.5) diameters between?
100 and 2500 nm (\$1\times10^{-7}\$ m and \$2.5\times10^{-6}\$ m)
28What are coarse particles (PM10) also commonly referred to as?
Dust
29What happens to the surface area to volume ratio as the side of a cube decreases by a factor of 10?
It increases by a factor of 10
30Why are nanoparticles more reactive than center atoms in bulk material?
Atoms on the surface are often more reactive, and nanoparticles have a very large surface area to volume ratio
31Why do nanoparticles make good catalysts?
They have a high surface area to volume ratio
32What are potential uses of carbon nanotubes in building materials?
Making stronger, lighter building materials
33Why are nanoparticles used in cosmetics like sun tan cream and deodorant?
They make no white marks
34How are nanoparticle lubricant coatings used?
To reduce friction in artificial joints and gears
35Why can carbon nanotubes be used in small electrical circuits for computers?
Because they conduct electricity
36Why are the full risks of nanoparticulate materials not fully known yet?
Because they are still being created and tested
37What is a major potential medical risk associated with nanoparticulate materials?
Problems with how they interact with our cells