Structure And Bonding

Question 1

Ionic structure

Answer 1

• giant lattice structure
• strong electrostatic forces of attraction between oppositely charged ions
• high melting and boiling points
• only conduct as liquid since that is when the ions are free to move

Question 2

What is an ion

Answer 2

An atom that loses or gains electrons to become charged

Question 3

Are polymers covalent or ionic

Answer 3

Giant covalent

Question 4

Metallic bonding

Answer 4

• electrons form a sea of electrons surrounding the positive metal ions
• delocalised electrons

Question 5

Limitation of particle models

Answer 5

• doesn’t show forces
• the particles aren’t solid spheres (as shown in the models)

Question 6

Properties of small molecules

Answer 6

• low boiling and melting points
• weak intermolecular forces between molecules
• can’t conduct

Question 7

Giant covalent structure + examples

Answer 7

• strong covalent bonds
• high melting point
• silicon dioxide , graphite and diamond

Question 8

Compare pure metals and alloys

Answer 8

Pure:
- arranged in layers of atoms of the same size so they are able to slide over each (malleable)

Alloys:
- consist of atoms of different sizes which disrupts the layers making it harder to slide over each other (stronger)

Question 9

Diamond

Answer 9

• each carbon is covalently bonded to 4 other carbons
• hard
• high melting point
• can’t conduct

Question 10

Graphite

Answer 10

• each carbon is covalently bonded to 3 other carbons
  -> forms hexagonal rings in layers
  -> layers have no covalent bonds and so can slide over each other
• weak intermolecular forces making it soft
• one electron from each carbon atom is delocalised so it can conduct

Question 11

Graphene

Answer 11

• single layer of graphite
• very strong

Question 12

Fullerenes

Answer 12

• hexagonal rings of carbon atoms with hollow shape
• spherical

Question 13

Nanotubes + their uses

Answer 13

• cylindrical fullerenes with high SA:V ratio
• Uses: to deliver drugs to the body, catalysts, lubricants

Question 14

Nanoparticles + uses

Answer 14

• high SA:V ratio
• uses: catalysts, cosmetics, lubricants
• disadvantage: could enter the bloodstream and be toxic

Question 15

Compare graphite and diamond

Answer 15

Diamond
- giant covalent lattice -> each C atom is bonded to 4 others which gives it a strong structure with strong covalent bonds

Graphite
- giant covalent lattice -> each C atom is bonded to 3 others
-> layers of hexagonal rings with weak intermolecular forces between layers this makes if soft as they can slide over each other
- can conduct as it has delocalised electrons

Both
- have high melting points -> giant covalent structure with many strong covalent bonds between atoms that need lots of energy to break

Question 16

Explain why copper is used to make electrical wiring and copper oxide isn’t

Answer 16

• copper is a transition metal with a giant metallic structure with strong electrostatic forces -> makes it have a higher boiling point and harder
• copper is also a good conductor of electricity as it has delocalised electrons that can carry charge through the structure
• copper oxide is ionically bonded with weak forces that don’t need a lot of energy to overcome -> so a low boiling point
• can’t conduct as a solid as the ions are fixed