C2.3 Properties Of Material Flashcards

1
Q

Why are metals malleable?

A

Metals are malleable because it has a sea of delocalised electrons. So when a large enough external force is applied the arrangement of particle can change by bending as since the eco trona are free to move around the electrostatic forces are still holding the particles together so no bonds are broken.

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2
Q

What happens to the forces of attraction when a substance goes from the solid state to the liquid state?

A

Some of the bonds break

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3
Q

The stronger the forces/bonds and the more there are…

A

the more energy will be required to break these forces/bonds.

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4
Q

Uses of nanoparticles

A
  • They have a large surface area to volume ratio so they can make good catalysts.
  • New cosmetic, eg.sun creams and deodorants, have been made using nanoparticles. The small particles do their job but they don’t leave white marks.
  • Nanomedicine. The idea is that tiny fullerenes are observed more easily by the body than most particles. This means they can deliver drugs right into the cells where they are needed.
  • New lubricant coatings are being developed using fullerenes. These coatings reduce friction a bit like really tiny ball bearings an could be used in all sort of places from artificial joints to gears.
  • Nanotubes conduct electricity, so they can be used in tiny electric circuits for computer chips.
  • Nanoparticles are added to plastics in sports equipment to make the plastic much stronger and more durable, without adding much mass.
  • Silver nanoparticles are added to polymer fibres used to make surgical masks and wounds dressings. This gives the fibres antibacterial properties.
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5
Q
Polymers
Giant covalent structure
Metallic bonding 
Simple covalent structures
Giant ionic lattices
Put these in order from highest boiling to point to lowest
A
Giant covalent structure 
Giant ionic lattices
Metallic bonding
Polymers
Simple covalent structures
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6
Q

When do bonds form in a substance?

A

When a substance condenses or freezes

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7
Q

Gas to liquid state. Describe the bonds

A

Some bonds form

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8
Q

What is a nanoparticulate?

A

It is a material made from nanoparticles

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9
Q

Where the does the energy go when a substance melts or boils

A

This energy comes from the surroundings into the substance to overcome the forces of attraction

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11
Q

Sublimation

A

When a substance changes directly from the solid state to the gas state.
Eg. Iodine. It exists as a simple molecule

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12
Q

What is the opposite of sublimation?

A

Deposition

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13
Q

How can a substance conduct electricity?

A

A substance can conduct electricity if it has charged particles that are free to move.

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14
Q

What happens to the forces of attraction when a substance goes from the liquid state to the gas state?

A

All the remaining bonds break

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16
Q

What is a nanoparticle?

A

A nanoparticle is a particle between 1nm and 100nm across, and consists of just a few hundred atoms.

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17
Q

Risks of nanoparticles

A

They are so tiny that they can be breathed in, absorbed by the skin or pass into cells
They take a long time to break down once released into the environment and toxic substances may stick to them
Risks are difficult to determine

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18
Q

Where does the energy go/come from when a substance condenses or freezes?

A

Energy is given out to the surroundings

18
Q

Why are substances brittle?

A

A brittle substance cracks or beaks when an external force is applied
This is because the particles can’t easily change their position in a brittle substance.

19
Q

When are are forever of attraction between a substance’s particle are overcome?

A

When the substance melts or boils

19
Q

Liquid to solid state

A

Many bonds form

20
Q

How can an ionic compound conduct electricity?

A

It can only conduct electricity when molten or in a solution because they contain oppositely charged ions which are free to move iPhone molten or in a solution.