Bonding, structure and properties of matter

Question 1

What are ions?

Answer 1

charged particles

Question 2

How do metals form ions?

Answer 2

-lose electrons from their outer shell to form positive ions

Question 3

How do non-metals form ions?

Answer 3

gain electrons into their outer shell to form negative ions

Question 4

What are positive and negative ions called?

Answer 4

positive- cations
negative- anions

Question 5

Describe ionic bonding

Answer 5

when a metal and a non-metal react with each other, the metal loses electrons to forma positive ion and the non-metal gains these electrons to form a negative ion. The oppositely charged ions are strongly attracted to another by electrostatic forces

Question 6

What is the structure of an ionic compound?

Answer 6

giant ionic lattice

Question 7

describe a giant ionic lattice

Answer 7

closely packed regular lattice arrangement with very strong electrostatic forces of attraction between oppositely charged ions

Question 8

What are the properties of an ionic compound?

Answer 8

• high melting and boiling points
• can only conduct electricity when molten or dissolved as there is a free moving ion

Question 9

Describe covalent bonding

Answer 9

• non-metals bond together and share pairs of electrons
• positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons by electrostatic forces
• only shares electrons in outer shells
• generally makes enough covalent bonds to fill up its outer shell

Question 10

What are simple molecular substances?

Answer 10

molecules containing a few atoms joined together by covalent bonds

Question 11

What are some examples of simple molecular substances?

Answer 11

• hydrogen
• chlorine
• oxygen
• nitrogen
• water
• methane
• hydrogen chloride

Question 12

What are the properties of simple molecular substances?

Answer 12

-forces of attraction between molecules are weak so low boiling point
- gases or liquids at room temp
- don’t conduct electricity

Question 13

What type of bonding is in a polymer?

Answer 13

covalent bonds

Question 14

What are the properties of a polymer?

Answer 14

• solids at room temp
• lower boiling points

Question 15

What are the properties of a giant covalent structure?

Answer 15

• very high melting and boiling points
• never conduct electricity
• strong covalent bonds

Question 16

What are some examples of giant covalent structures?

Answer 16

• diamond
• graphite
• silicon dioxide

Question 17

Describe the structure of diamond

Answer 17

• very rigid giant covalent structure
• each carbon atom forms four covalent bonds

Question 18

Describe the structure of graphite

Answer 18

• giant covalent structure
• each carbon atom forms three covalent bonds to create layers of hexagons
• each carbon also has one delocalised electron

Question 19

Describe the structure of silicon dioxide

Answer 19

• giant covalent structure
• what sand is made of
• each grain of sand is one giant structure of silicon and oxygen

Question 20

What is an allotrope?

Answer 20

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

Question 21

What are the properties of diamond?

Answer 21

• really hard
• very high melting point
• doesn’t conduct electricity

Question 22

Why is graphite ideal as a lubricant?

Answer 22

there aren’t any covalent bonds between the layers- they are held together weakly so are free to move over each other- makes graphite soft and slippery

Question 23

What is graphene

Answer 23

a sheet of carbon atoms joined together in hexagons- one atom thick making it a two-dimensional substance

Question 24

What are the properties of graphene?

Answer 24

• very strong
• very light
• can conduct electricity throughout the whole structure

Question 25

What is graphene used for?

Answer 25

• improve the strength of composite materials without adding much weight
• has the potential to be used in electrons

Question 26

What are fullerenes?

Answer 26

molecules of carbon shaped like closed tubes or hollow balls

Question 26

Describe the structure of fullerenes

Answer 26

• mainly made up of carbon atoms arranged in hexagons- can also contain pentagons and heptagons

Question 27

What are the uses of fullerenes?

Answer 27

• to deliver drugs into the body
• industrial catalysts
• lubricants
• to form nanotubes

Question 28

What are the properties of nanotubes?

Answer 28

• conduct both electrical and thermal energy
• high tensile strength

Question 29

Describe metallic bonding

Answer 29

• metals have delocalised electrons in their outer shell which has strong forces of electrostatic attraction to the positive metal ions
• these forces of attraction hold the atoms together in a regular structure

Question 30

Why are alloys harder than pure metals?

Answer 30

because the different elements have different sized atoms and the layers of metal atoms will distort and it will become more difficult for them to slide over each other

Question 31

What is the diameter of a nanoparticle?

Answer 31

between 1nm and 100nm

Question 32

What are nanoparticles used for?

Answer 32

• nanomedicine (delivering drugs into the body)
• tiny electric circuits for computer chips
• silver nanoparticles have antibacterial properties- surgical masks, wound dressings and deodrants
• used in cosmetics to improve moisturisers