Nanoparticles And Polymers

Question 1

What are non particles

Answer 1

A nanoparticle is a tiny particle with a size between 1–100 nanometers, containing only a few hundred atoms.

Question 2

Why are nanoparticles useful

Answer 2

Nanoparticles have a high surface area to volume ratio, which gives them unique properties useful in medicine, electronics, and cosmetics.

Question 3

Why are nano particles good catalysts

Answer 3

High surface area to volume ratio meaning more collisions can take place

Question 4

Size of nano particles

Answer 4

Between 1nm and 100nm in diameter

Question 5

1nm in m

Answer 5

1*10^-9 metres

Question 6

Sodium chloride has a melting point of 801oC.
Use the structure of sodium chloride to explain why.

The diagram is a diagram using lines to show bonds and circles to show a anions and cations

Answer 6

-> strong electrostatic forces of attraction between ions
-> muse be broken to melt NaCl

Question 7

Graphite is a good conductor of electricity.
Diamond does not conduct electricity.

Use ideas about structure and bonding in diamond and graphite to explain these observations.

Answer 7

Graphite - has a layered structure, and delocalised lecterns can move through these layers to carry charge
Diamond - no free electrons to carry electrical charge

Question 8

Why can carbon form many thousands of different compounds?

Answer 8

It is able to bond to itself and make chains and rings

Question 9

Relationship between boiling points, number of carbon atoms and intermolecular force

Answer 9

LOW boiling point means there’s LESS than 20 carbon atoms and the size of intermolecular forces is SMALL

Question 10

Inga does the experiment with copper, zinc and dilute sulfuric acid again.
This time she uses a lump of copper rather than copper powder.
Predict, with reasons, the relative rate of reaction.

Answer 10

• The rate of reaction will be less than with just copper powered, but will be faster than other substances.
• This is due to the copper powder having a higher surface area to volume ratio than the lump of copper meaning more collisions take place with the powder

Question 11

What are thermosoftening polymers

Answer 11

They are plastics which will soften when heated and can be reshaped.

Question 12

What are thermosetting polymers

Answer 12

Thermosetting plastics are plastics do not soften on heating. They are used when heat resistance is important

Question 13

Why do thermosetting polymers withstand heat

Answer 13

Thermosetting polymers are fire-resistant because their cross-linked molecular structure prevents melting

Question 14

What does it mean to be made of cross linked molecules

Answer 14

Cross-linked molecules are polymer chains that are chemically bonded together by strong covalent bonds,

Question 15

Structural differences between thermosetting and Thermosoftening polymers

Answer 15

Thermos softening - long tangles chains of molecules with weak intermolecular forces between them beaming low energy is needed to break them apart

Thermosetting - strong covalent cress links between molecules which means it takes a high amount of energy to melt

Question 16

Compare ‘nano’ dimensions to typical dimensions of atoms and molecules:

Answer 16

Nanoparticles range from 1 to 100 nanometres (nm) in size, which is about the same size as large molecules and only a few times bigger than individual atoms (0.1 nm).

Question 17

Describe the surface area to volume relationship for different-sized particles and describe how this affects properties

Answer 17

As particle size decreases, the surface area to volume ratio increases, making nanoparticles more reactive and giving them unique properties like improved catalysts

Question 18

Describe how the properties of nanoparticulate materials are related to their uses

Answer 18

Nanoparticles have high reactivity, strength, and unique optical properties, making them useful in
- medicine (drug delivery),
- cosmetics (sunscreens),
- electronics (conductive materials).

Question 19

Explain the possible risks associated with some nanoparticulate materials

Answer 19

• Nanoparticles can be toxic if inhaled or absorbed, potentially causing lung damage or environmental harm
• their small size makes it difficult to track their long-term effects.

Question 20

What are the three most common fullerenes of carbon

Answer 20

Buckminsterfullerene (C₆₀) – A spherical molecule made of 60 carbon atoms arranged in a football-like structure.

Carbon nanotubes – Cylindrical fullerenes with high strength and electrical conductivity.

C₇₀ fullerene – Similar to C₆₀ but with 70 carbon atoms, giving it a more elongated shape

Question 21

What are fullerenes

Answer 21

Fullerenes are carbon allotropes where carbon atoms form hollow structures like spheres or tubes

Question 22

Differences between fullerines and diamonds

Answer 22

Fullerenes can conduct electricity because they have delocalised electrons within their structure

Diamond does not conduct electricity because all its electrons are held in strong covalent bonds and cannot move freely

Question 23

Graphite is used to make pencil leads.
Explain why the properties of graphite make it suitable for pencil leads

Answer 23

Graphite has weak intermolecular forces between layers, meaning that they are able to easily slide over eachother and leave marks on the page.