physical properties

Question 1

intramolecular bond

Answer 1

bond which occurs BETWEEN atoms INSIDE molecules

Question 2

intermolecular forces

Answer 2

forces of attraction BETWEEN molecules,ions,atoms,noble gases

Question 3

van der Waals forces

Answer 3

intermolecular forces of varying strength specifically between molecules

Question 4

london force

Answer 4

weakest van der Waals force
due to the attraction of electrons of one molecule between to the nuclei of another
exists between non polar molecules

Question 5

hydrogen bond force

Answer 5

force between highly polar molecules which is a special case of van der Waals forces between polar molecules

stronger than forces between other polar molecules

Question 6

interaction

Answer 6

bond/force between particles (atoms,molecules, ions,electrons) of substance responsibility for its physical properties

Question 7

melting and boiling points

Answer 7

depends on strength and number of interactions betel particles
more,stronger forces= higher MP + BP

Question 8

conductivity

Answer 8

ability for current to flow through substance

substance must contain charged particles (ions,electrons) that are free to move

Question 9

malleable

Answer 9

bendability

hard materials ability to be hammered/ pressed into shape w/o breaking/cracking

Question 10

brittle

Answer 10

hard material that will break/crack when subjected to force.

Question 11

types of solids

Answer 11

metallic lattice
ionic lattice
molecular lattice
atomic lattice

Question 12

what are the particles in a metallic lattice

Answer 12

positive kernels and delocalised electrons

Question 13

how is a metallic lattice formed

Answer 13

it is a result of metallic bonding

Question 14

metallic lattice strength

Answer 14

strong, generally hard

Question 15

metallic lattice MP+BP

Answer 15

high MP and BP

• many strong electrostatic forces of attraction between positive kernels and delocalised electrons
• more energy need to overcome forces of attraction

Question 16

metallic lattice conductivity

Answer 16

good conductors of electricity in all phases

- delocalised electrons can move over positive kernels

Question 17

metallic lattice malleability

Answer 17

sheets of cations can slide over each other but remain held together by electrostatic forces of attraction between electrons and cations

Question 18

ionic lattice strength

Answer 18

strong

Question 19

ionic lattice particles

Answer 19

anions and cations

Question 20

MP + BP ionic lattice

Answer 20

high
many strong electrostatic forces of attraction between anions and cations
more energy needed to overcome forces

Question 21

why one w greater BP - ionic lattice

Answer 21

electrostatic forces between - are stronger than those between - bcus the size of the charges are greater in -
more energy required to overcome forces

Question 22

ionic lattice brittle

Answer 22

a shift in the arrangement of ions brings like charges alongside each other which result in a force of repulsion which causes the solid to fracture

Question 23

conductivity ionic lattice

Answer 23

in solid state, cations and anions are not free to move to carry charge in ionic lattice
-cannot conduct electricity in solid state

Question 24

when can ionic lattice conduct electricity

Answer 24

aqueous state/molten state

-ions are free to move to carry charge

Question 25

molecular lattice particles

Answer 25

molecules held together by electrostatic forces

Question 26

van der waals forces from weak to strong

Answer 26

london forces of attraction dipole dipole forces of attraction hydrogen bond force

Question 27

strength molecular lattice

Answer 27

generally weak when compared

Question 28

london force bond

Answer 28

electrons randomly move around molecule | at a point in time e-‘s can exist on one side more

Question 29

metallic lattices conduct electricity in solid state

Answer 29

The lattice contains delocalised electrons which are free to move to carry charge

Question 30

Explain why metallic lattices have generally high melting points

Answer 30

◦There are many, strong electrostatic forces between cations and delocalised electrons in the lattice ◦More energy is required to overcome these forces

Question 31

Explain why aluminium has a higher melting point than magnesium.

Answer 31

◦Both substances are metallic ◦Aluminium cations have a 3+ charge and magnesium cations have a 2+ charge ◦The electrostatic forces of attraction between the cations of aluminium and the delocalised electrons are stronger than those in magnesium ◦More energy is required to overcome the stronger forces in the aluminium lattice ◦Therefore aluminium has a higher boiling point than magnesium

Question 32

Explain why metals are malleable.

Answer 32

◦The sheets of positive cations can slide over one another while the electrostatic forces mm between the cations and delocalised electrons remain intact ◦The lattice can be bent into different shapes

Question 33

why ionic lattices cannot conduct electricity in the solid state.

Answer 33

◦The ions (cations and anions) are not free to move to carry charge in the solid state

Question 34

Why are ionic substances brittle?

Answer 34

◦When a force is applied to the ionic lattice the arrangement of the ions can change so that like charges are next to each other. ◦Like charges repel each other ◦The lattice shatters

Question 35

Explain why ionic substances generally have a high melting point.

Answer 35

◦There are many, strong electrostatic forces between cations and anions in an ionic lattice ◦More energy is required to overcome these forces

Question 36

Which substance would have a higher melting point? Magnesium oxide or lithium bromide.

Answer 36

Both substances are ionic ◦In magnesium oxide the cations have a 2+ charge and the anions have a 2- charge ◦In lithium bromide the cations have a 1+ charge and the anions have a 1- charge ◦The electrostatic forces of attraction between ions (cations and anions) are stronger in the magnesium oxide lattice as a result ◦More energy is required to overcome stronger forces ◦Magnesium oxide has a higher boiling point than lithium bromide

Question 37

) Do atomic lattices have generally high or low melting points. Explain fully.

Answer 37

◦High melting point | ◦Many strong covalent bonds holding atoms together ◦More energy is required to break these bonds.

Question 38

Which has a higher melting point? Diamond or graphite? Explain fully.

Answer 38

◦Diamond ◦Each carbon atom is bonded 4 times with other carbons compared to graphite where each carbon atom is bonded only 3 times with other carbon atoms ◦More energy is required to break the many strong covalent bonds in diamond

Question 39

) Which atomic lattice can conduct electricity in the sold phase? Explain.

Answer 39

Graphite ◦Each carbon atom has a delocalised electron that is not bonded ◦These electrons are free to move to carry charge

Question 40

london force origin

Answer 40

Electrons move randomly around particles By chance one molecule can form a temporary dipole When this temporary dipole comes close to a neighbouring molecule the neighbouring molecule forms an induced dipole The two dipoles electrostatically attract

Question 41

hydrogen bond force origin

Answer 41

when a small highly electronegative atom( N,O,F) bonds with hydrogen, hydrogen bonding can occur THE highly electronegative atom attracts the bonding pair of e- away from hydrogen exposing a naked proton the naked proton electrostatically attracts the lone pair of e- of a neighbouring molecule

Question 42

molecular lattice MP/BP

Answer 42

low weak van der waals forces between molecules less energy required to overcome forces

Question 43

molecular lattice conductivity

Answer 43

cannot conduct electrical charge neutral molecules no charges to move to carry charge

Question 44

molecular lattice phase change

Answer 44

intermolecular forces overcome

Question 45

molecular lattice chemical change

Answer 45

intramolecular bonds broken

Question 46

atomic lattice types

Answer 46

diamond graphite silicon dioxide

Question 47

atomic lattice strength

Answer 47

extremely strong many strong covalent bonds between atoms more energy needed to break the bonds

Question 48

diamond bonds per atom

Answer 48

4

Question 49

graphite bonds per atom

Answer 49

3

Question 50

silicon dioxide bonds per atom

Answer 50

bonds per atom

Question 51

graphite

Answer 51

covalent bonds between atoms sheets of carbon held together by weak electrostatic forces of attraction- london forces held by delocalised e- - can conduct electricity

Question 52

why silicon dioxide poor conductor

Answer 52

atoms are neutral | no particles to move to carry charge

Question 53

what influence strength of intermolecular forces

Answer 53

the type of intermolecular force involved e.g.: weak van der Waals forces (such as London forces) vs stronger hydrogen bonds. • The number of electrons in the molecule which is indicated by the molar mass of the molecule (for London forces only). • The number of intermolecular forces (relates to hydrogen bonds only)