C2.2

Question 1

What can’t simple molecules do?

Answer 1

Conduct electricity

Question 2

The ions within a giant ionic lattice are held together by what?

Answer 2

Strong electrostatic forces

Question 3

What are some features of ionic compounds?

Answer 3

~ High melting points

~ High boiling points

Question 4

What is the name of the compound for salt?

Answer 4

Sodium chloride

Question 5

What causes the high melting and boiling points in ionic compounds?

Answer 5

~ Strong electrostatic forces of attraction

~ Lots of energy is needed for the ions to break away from the forces of attraction

Question 6

Why does silicon dioxide have high melting and boiling points?

Answer 6

Because of its strong covalent bonds

Question 7

Why can graphite conduct heat and electricity?

Answer 7

~ Each carbon atom only forms 3 bonds with other carbon atoms
~ So each carbon atom has a delocalised electron which can pass on the electricity

Question 8

How are the atoms in a metal arranged?

Answer 8

Neatly in rows

Question 9

Why can a metal conduct heat and electricity?

Answer 9

It has delocalised electrons that are free to move and pass the electricity on

Question 10

Why are all the atoms in a metal positively charged?

Answer 10

Because they’ve lost an electron, which is free to move

Question 11

How are the positive ions and delocalised electrons held together in a metallic bond?

Answer 11

With strong electrostatic forces of attraction

Question 12

Why are pure metals usually malleable?

Answer 12

~ They’re arranged in neat rows and columns

~ Layers can slide over each other

Question 13

What does malleable mean?

Answer 13

Easily hammered or bent into shape

Question 14

Why might alloys be made?

Answer 14

~ To change colour

~ To make metals much harder

Question 15

What is the alloy nitinol made of?

Answer 15

Nickel and titanium

Question 16

What are the properties of nitinol?

Answer 16

~ Shape can be changed when cooled

~ When heated it will go back into its original shape

Question 17

Why is nitinol used as dental braces?

Answer 17

~ It can be cooled and wrapped around the teeth
~ The warmth of the mouth will cause the brace to try to get back to its original shape
~ This causes it to put pressure on the teeth and move them to a correct position

Question 18

How is nitinol used to repair broken bones?

Answer 18

~ It’s cooled then wrapped around the bones
~ The body warmth will cause the nitinol to try to return to its original shape
~ This causes the nitinol to contract and hold the bones together as they repair

Question 19

Why do metals have electrons that are free to move?

Answer 19

Because metals have electrons in the outer shell of the atoms that can move away from the atom, meaning they are delocalised

Question 20

What does increasing the pressure do to polyethene?

Answer 20

Makes low density polyethene which has a lower melting point

Question 21

What affects the density of polyethene?

Answer 21

The arrangement of the polymer chains, if they are closer together the forces of attraction between them will be stronger

Question 22

What is a property of high density polyethene?

Answer 22

It has a high melting point

Question 23

What are the forces of attraction like in low density polyethene?

Answer 23

Weaker because the polymers are further apart

Question 24

What are properties of thermosoftening polymers?

Answer 24

Easily changed shape

Question 25

What do thermosoftening polymers make?

Answer 25

Plastic bags

Question 26

What are properties of thermosetting polymers?

Answer 26

Don't change shape when heated

Question 27

What bonds do thermosetting polymers have in them?

Answer 27

Strong covalent bonds which links the separate polymer chains

Question 28

What do thermosetting polymers make?

Answer 28

~ Plugs ~ Cooking spatulas ~ Panhandles

Question 29

Why are thermosoftening polymers easy to separate?

Answer 29

~ Weak intermolecular forces of attraction ~ Polymers can separate more easily at lower temperatures ~ Less heat energy is needed to separate the polymer chains

Question 30

Why can't simple molecules conduct electricity?

Answer 30

Because the molecules have no overall charge

Question 31

What may nanoparticles lead to the development of?

Answer 31

~ New computers ~ New catalysts ~ New cosmetics

Question 32

What does sonorous mean?

Answer 32

Metals ring like a bell when hit, not a dull thud

Question 33

What does ductile mean?

Answer 33

Metals can be drawn into wires

Question 34

What does lustrous mean?

Answer 34

All metals are shiny when polished or cut

Question 35

What is the test for carbon dioxide?

Answer 35

Makes a lit splint go out, or makes limewater go cloudy

Question 36

What is a displacement reaction?

Answer 36

When a less reactive metal reacts with a more reactive metal solution, so the solution displaces the solid and nothing really happens