bonding, structure and properties of matter

Question 1

what is ionic bonding

Answer 1

• when a metal and non-metal form a compound

- a metal will give a non-metal it’s excess electrons

Question 2

how are the elements in an ionic compound held together

Answer 2

electrostatic forces

Question 3

what is the structure of an ionic compound

Answer 3

regular lattice structure

Question 4

what are the properties of ionic compounds

Answer 4

• high melting and boiling points due to many strong ionic bonds
• can conduct electricity when in liquid form

Question 5

what is covalent bonding

Answer 5

• when two non-metals share electrons

- they both need more electrons for a full outer shell so they have to share

Question 6

what are the disadvantages of a displayed formula

Answer 6

• doesn’t show the relative size

- doesn’t show the shape and arrangement

Question 7

what are the type of substances covalent bonds can make

Answer 7

• simple molecular substances eg. H2O, Cl2
• polymers
• giant covalent structures eg. diamond and graphite

Question 8

describe the strength of the bonds that hold simple molecular structures together

Answer 8

• a simple molecule has multiple atoms covalently bonded together, these covalent bonds between atoms are very strong
• however the forces of attraction between separate molecules are weak

Question 9

why do simple molecular substances have low melting and boiling points

Answer 9

only the weak forces of attraction that hold the separate molecules together need to be broken which requires little energy

Question 10

what is the general structure of giant covalent structures like

Answer 10

regular repeating lattice

Question 11

what is an allotrope

Answer 11

different structural forms of the same element in the same physical state

Question 12

what is the maximum number of bonds carbon can make

Answer 12

4

Question 13

what are the properties of diamond

Answer 13

• very strong due to all the covalent bonds
• high melting and boiling points
• cannot conduct electricity

Question 14

what are the properties of graphite

Answer 14

• layers of flat hexagonal sheets
• soft as the layers are held together weakly
• can conduct electricity as each carbon atom has 1 free electron (delocalised)
• high melting and boiling point

Question 15

what is graphene

Answer 15

a single layer of graphite

Question 16

what are fullerenes

Answer 16

tiny tubes and spheres made from graphene

Question 17

what are fullerenes used for

Answer 17

• formed around drugs to deliver them into the body
• large surface area to volume ratio so they can be used as industrial catalysts
• nanotechnology as they can conduct electricity
• strength other materials

Question 18

what is a buckminsterfullerene

Answer 18

one of the first fullerenes made, hollow sphere made of 60 carbon atoms

Question 19

what is metallic bonding

Answer 19

the type of bonding you get between metal ions

Question 20

what is the structure of metallic bonding

Answer 20

• metal ions arranged in a regular pattern
• outer shell electrons are delocalised
• strong electrostatic attraction between positive ions and negative electrons

Question 21

what are the properties of metallic bonding

Answer 21

• can carry electric current and thermal energy

- malleable (pure metals)

Question 22

what is an alloy

Answer 22

mixing together 2 or more different metals

Question 23

why do we use alloys

Answer 23

disturbing the regular structure with different sized atoms makes them harder than pure metals

Question 24

what is wrong with the particle model

Answer 24

• particles are solid, inelastic or spheres

- doesn’t include details like how many or how strong the forces are

Question 25

what is a nanoparticle

Answer 25

tiny particles with a diameter of 1nm to 100nm

Question 25

what is a nanoparticle

Answer 25

tiny particles with a diameter of 1nm to 100nm

Question 26

what are the key features of nanoparticles.

Answer 26

• large surface area to volume ration

Question 27

what is the key feature of nanoparticles

Answer 27

large surface area to volume ration

Question 28

what can nanoparticles be used for

Answer 28

• catalysts
• nano medicine (delivery drugs)
• electrical circuits
• silver nanoparticles for its antibacterial properties

Question 29

what are the risks of using nanotechnology

Answer 29

• relatively new so not a lot of research
• effects on our body aren’t fully understood
• need to be tested more
• might damage the environment