Bonding structure and properties of matter

Question 1

group 1 and 2 elements are most likley to form ions

Answer 1

• metals
• lose electrons
• form positive ions
• cations

Question 2

group 6 and 7 are most likely to form ions

Answer 2

• non-metals
• gain electrons
• form negative ions
• anions

Question 3

describe the ionic compound’s structure: the giant ionic lattice

Answer 3

• ions form closely packed regular lattice arrangement
• strong electrostatic forces of attraction
• between oppositely charged ions
• in all directions of lattice

Question 4

ionic compounds all have similiar properties

Answer 4

• high melting/boiling points
• solid: can’t conduct electricity
• soluble

Question 5

why do ionic compounds have high melting/boiling points?

Answer 5

• many strong bonds between ions
• lots of energy needed to overcome

Question 6

why do solid ionic compounds not conduct electricity?

Answer 6

• ions held in place
• melted: ions free to move carry current

Question 7

what happens when ionic compounds dissolve in water?

Answer 7

• ions seperate
• free to move
• carry electric current

Question 8

what are simple molecular substances?

Answer 8

• made up of molecules containing few atoms
• joined by covalent bonds

Question 9

what are the properties of the simple molecular substances?

Answer 9

• atoms within molecules very strong covalent bonds
• low melting/boiling points
• gases/liquid at room temp
• don’t conduct electricity

Question 10

although simple molecular structures have very strong covalent bonds…

Answer 10

the forces of attraction between these molecules are very weak

Question 11

why do simple molecular structures have low melting/boiling points?

Answer 11

• only need to break feeble intermolecular forces
• molecules easily parted

Question 12

what happens when a molecular substance gets bigger?

Answer 12

• strength intermolecular forces increase
• more energy to break
• melting/boiling point increase

Question 13

why do molecular compounds not conduct electricity?

Answer 13

• aren’t charged
• no free electrons/ions

Question 14

what are polymers?

Answer 14

• long chains
• repeating small units

Question 15

atoms in a polymer are joined by…

Answer 15

strong covalent bonds

Question 16

why are polymers solid at room temp?

Answer 16

• intermolecular forces between molecules larger
• more energy needed to break them

Question 17

why do polymers have low boiling points?

Answer 17

• intermolecular forces weaker than ionic or covalent bonds
• lower boiling point than ionic or giant molecular compounds

Question 18

what are macromolecules?

Answer 18

• giant ocvalent structure
• atom strongly covalent bond
• very high melting/boiling point
• don’t conduct electricity: no charged particles

Question 19

describe the macromolecule of diamond

Answer 19

• each carbon atom forms 4 covalent bonds
• very rigid giant covalent structure

Question 20

decribe the macromolecule of graphite

Answer 20

• each carbon atom forms 3 covalent bonds
• create hexagon layers
• each carbon atom has one delocalised electron

Question 21

decribe the macromolecule of silicon dioxide

Answer 21

• sand made of silica
• each grain one giant structure of silicon and oxygen

Question 22

what are the properties of a diamond?

Answer 22

• giant covalent structure makes it really hard
• very high melting point: strong covalent bonds lots energy to break
• doesn’t conduct electricity: no free electrons/ions

Question 23

how does graphite containing sheets of hexagons make it ideal as lubricating material?

Answer 23

• soft and slippery
• no covalent bonds between layers
• held weakly, free to move over eachother

Question 24

why does graphite have a high melting point?

Answer 24

• lots energy to break
• covalent bonds in layer

Question 25

why can graphite conduct electricity and thermal energy?

Answer 25

- 3/4 outer electrons used in bonds - one free electron can move

Question 26

what is graphene?

Answer 26

- sheet of carbon atoms joined in hexagons - one atom thick - two-dimensional compound

Question 27

what are the properties of graphene?

Answer 27

- strong: network of covalent bonds - light: add to composite materials improve strength without added weight - conduct electricity through whole structure

Question 28

what are fullerenes?

Answer 28

- molecules of carbon - shaped close tubes/hollow balls

Question 29

how are carbon atoms arranged in fullerenes?

Answer 29

- mainly hexagons - pentagons - heptagons

Question 30

how can fullerenes be used to deliver a drug into the body?

Answer 30

-structure cages other molecules

Question 31

why can fullerenes make great industrial catalysts?

Answer 31

-large surface area

Question 32

what is the buckminsterfullerene?

Answer 32

- first discovered - molecular formula C₆₀ - hollow sphere

Question 33

what is metalic bonding?

Answer 33

- delocalised electrons in outer shell of metal atom - strong froces of electrostatic attraction - between positive metal ions and shared negative electrons

Question 34

why are most metals solid at room temp?

Answer 34

- strong electrostatic forces of attraction - lots energy to break - very high melting/boiling point

Question 35

why are most metals malleable?

Answer 35

-layers of atoms slide over eachother

Question 36

what are alloys?

Answer 36

- mixture of two or more metals - different sized atoms - distorted layers - pure metals too soft

Question 37

how are alloys harder than pure metals?

Answer 37

- different element shave different sized atoms - new metal atoms ditort layers of metal atoms - more difficult to slide over eachother

Question 38

the state of something at a certain temp depends on...

Answer 38

how strong forces of attraction are between particles of material

Question 39

how strong froces of attraction are depends on...

Answer 39

- material - temp - pressure

Question 40

explain the particle theory of a solid

Answer 40

1. strong forces of attraction between particles, holds close together in fixed position to from lattice arangement 2. definite shape and volume 3. vibrate about their positions

Question 41

explain the particle theory of a liquid

Answer 41

1. weak forces of attraction between particles, randomly arranged, move past eachother, stick together 2. definite volume, don't keep definite shape 3. constantly move in random motion

Question 42

explain the particle theory of a gas

Answer 42

1. very weak forces of attraction, free to move, far apart 2. don't keep definite shape or volume 3. move constantly in random motion

Question 43

solid melted to liquid

Answer 43

- particles gain more energy - vibrate more: weakens forces - melting point: enough energy to break free

Question 44

liquid boiled to gas

Answer 44

- particles gain more energy - more faster: weakens and breaks bonds - boiling point: enough energy to break bonds

Question 45

gas condensed to liquid

Answer 45

- cools: particles no longer have enough energy overcome forces - bonds form - boiling point: many bonds form gas to liquid

Question 46

liquid freezed to solid

Answer 46

- cools: particles have less energy - not enough energy to overcome forces: more bonds form - melting point: so many bonds form liquid to solid

Question 47

what are coarse particles (PM₁₀)?

Answer 47

- dust - diameter: 2.5x10^-6m and 1x10^-5m

Question 48

what are fine particles (PM_2.5)?

Answer 48

-diameter: 1x10^-7m and 2.5x10^-6m

Question 49

how can you calculate the surface area to volume ratio?

Answer 49

surface area/volume

Question 50

how is electricity conducted in a metal?

Answer 50

- giant ionic lattice - made up of positive ions - with free electrons - moves to carry charge

Question 51

why is alloys used in dental braces?

Answer 51

-turn back into original shape

Question 52

why are instrumental methods used to detect impurities on metals?

Answer 52

- accurate - small samples