Giant covalent structures

Question 1

what are polymers

Answer 1

long chains of repeating units

Question 2

what are atoms in a polymer joined by

Answer 2

strong covalent bonds

Question 3

what are atoms in a giant covalent structure joined together by

Answer 3

strong covalent bonds

Question 4

properties of giant covalent structures

Answer 4

• high melting and boiling points, lots of energy needed to break these
• don’t contain charged particles, so they don’t conduct electricity, not even when molten, graphite is an exception

Question 5

Diamond properties

Answer 5

• made from carbon atoms in a very rigid giant covalent structure
• made up of carbon atoms that each form 4 covalent bonds, making it very hard
• these bonds need a lot of energy to break, making diamond have a very high melting point
• doesn’t conduct electricity as it has no free electrons or ions

Question 6

Graphite properties and uses

Answer 6

• each carbon atom only forms 3 covalent bonds, creating sheets of carbon atoms arranged in hexagons
• no covalent bonds between the layers, held together weakly, so free to move over each other - making it soft and slippery
• high melting point
• ideally used for lubricants and pencils

Question 7

why can graphite conduct electricity

Answer 7

• because only 3 of each carbons 4 outer electrons are used in bonds, so each carbon atom has one electron thats delocalized ( free ) and can move, so graphite conducts electricity and heat

Question 8

Graphene properties and uses

Answer 8

• one layer of graphite
• one sheet of carbon atoms joined together in hexagons, one atom thick, 2D substance
• network of covalent bonds makes it very strong
• very light, added to composite materials to add strength without adding much weight
• can conduct electricity because of the same reason as graphite
• can be used in electronics

Question 9

Buckminsterfullerene properties and uses

Answer 9

• molecular formula c60
• molecules of carbon shaped like HOLLOW SPHERES
• can be used to cage other molecules, could be used to deliver a drug into the body
• huge surface area so can be used as a catalyst
• fullerenes can form nanotubes- tiny carbon cylinders

Question 10

fullerene uses

Answer 10

lubricants