2. Bonding, structure and the properties of matter (polymers, states of matter, bulk and surface properties of matter)

Question 1

What are polymers?

Answer 1

very large molecules with atoms linked by covalent bonds

Question 2

What are the limitations of the simple model?

Answer 2

• there are no forces between spheres and atoms
• molecules and ions are solid sphere - this is not true

Question 3

What are the strength of the forces between particles determined by?

Answer 3

1. The material (the structure and type of bonds holding it together)
2. The temperature
3. The pressure

Question 4

When will a pure substance melt or boil at?

Answer 4

a fixed temperature

Question 5

When will a mixture melt or boil at?

Answer 5

over a range of temperatures

Question 6

What is nanoscience?

Answer 6

science that studies particles that are 1-100nm in size

Question 7

State the uses of nanoparticles?

Answer 7

1. medicine (drug delivery systems)
2. electronics
3. deodorants
4. sun creams

Question 8

What are fine particles?

Answer 8

• fine particles (soot) 100-2500nm diameter

Question 9

What are coarse particles?

Answer 9

Question 10

Why do nanoparticles have different properties to those for the same materials in bulk?

Answer 10

due to high surface area to volume ratio

Question 11

Equation for surface area to volume ratio?

Answer 11

surface area/volume

Question 12

What are the possible disadvantages of nanoparticles?

Answer 12

• there are some concerns that nanoparticles may be toxic to people
• they may be able to enter the brain from the bloodstream and cause harm

Question 13

As particles get smaller what increases?

Answer 13

its surface area to volume ratio

Question 14

How many atoms do nanoparticles contain?

Answer 14

a few hundred atoms