topic 1 - structure and bonding

Question 1

ion

Answer 1

a charge particle

Question 2

anion

Answer 2

a negative ion

formed through electron gain

Question 3

what groups form anions

Answer 3

6 and 7

Question 4

cation

Answer 4

a positive ion

formed through electron loss

Question 5

what groups readily form cations

Answer 5

1 and 2

Question 6

how is an ionic bond formed

Answer 6

a metal atom loses electrons to form a cation
a non metal atom gains these electrons to form an anion
the two oppositely charged ions are strongly attracted to one another by ELECTROSTATIC FORCES

Question 7

ions ending in -ate

Answer 7

negative

contain oxygen and at least one other element

Question 8

ions ending in -ide

Answer 8

negative

only contain one element (excluding hydroxide)

Question 9

structure of ionic compounds

Answer 9

regular, giant ionic lattice held together by strong electrostatic forces between oppositely charged ions

Question 10

properties of ionic compounds

Answer 10

high melting and boiling points

conduct electricity when molten or aqueous

Question 11

why do ionic compounds have high melting and boiling points

Answer 11

takes a lot of energy to overcome the strong electrostatic attraction

Question 12

why do ionic compounds conduct electricity when molten or aqueous

Answer 12

when solid, the ions are held in place so can’t conduct electricity
when molten/aqueous, ions are free to move and therefore can carry electric current

Question 13

covalent bond

Answer 13

a strong bond formed when a pair of electrons is shared between two atoms

Question 14

covalent bond features

Answer 14

weak intermolecular forces
uses non metal atoms
creates molecules

Question 15

properties of simple covalent compounds

Answer 15

low melting and boiling points

poor conduction of electricty

Question 16

why do simple covalent compounds have low melting and boiling point

Answer 16

the intermolecular forces are weak so not much energy is needed to overcome them

Question 17

why do simple covalent compounds not conduct electricity well

Answer 17

they contain uncharged atoms so there are no free ions or electrons to carry the current

Question 18

properties of giant covalent structures

Answer 18

very high melting and boiling points
don’t conduct electricity (apart from graphite and graphene)
insoluble in water

Question 19

what giant covalent structures can conduct electricity

Answer 19

graphite

graphene

Question 20

why do giant covalent structures have VERY high melting and boiling points

Answer 20

lots of energy is needed to overcome the strong covalent bonds

Question 21

give 4 examples of giant covalent structures

Answer 21

diamond
graphite
graphene
C60 - buckminsterfullerene

Question 22

diamond

Answer 22

network of carbon atoms that each form 4 covalent bonds

Question 23

properties of diamond and their reasons

Answer 23

high melting and boiling points - strong covalent bonds (strong intermolecular forces)

very hard - strong, rigid lattice structure

no conduction of electricity - no free ions or electrons

Question 24

use of diamond

Answer 24

cutting tools

Question 25

graphite

Answer 25

a carbon structure where carbon atoms have three covalent bonds and the 4th electron is delocalised this creates sheets of carbon atoms arranged in hexagons

Question 26

properties of graphite and their reasons

Answer 26

high melting point - strong covalent bonds (strong intermolecular forces) conduction of electricity - the delocalised electron is free to move soft and slippery - layers don't have covalent bonds between them, allowing them to slide over one another

Question 27

uses of graphite

Answer 27

electrodes | lubrication

Question 28

allotrope

Answer 28

multiple forms of the same element

Question 29

fullerene

Answer 29

carbon molecules shaped like a tube/cylinder or hollow ball | can trap molecules

Question 30

graphene

Answer 30

one layer of graphite

Question 31

properties of graphene

Answer 31

high melting point | conducts electricity

Question 32

what can graphene form and what can that be used for

Answer 32

can form carbon nanotubes these have high tensile strength used to strengthen lightweight sports equipment

Question 33

what does C60 look like

Answer 33

hollow sphere 20 hexagons 12 pentagons

Question 34

polymer

Answer 34

large molecules containing long chains of covalently bonded carbon atoms formed by lots of monomers joining together

Question 35

metallic bond

Answer 35

bond between metal ions and delocalised electrons due to electrostatic attraction

Question 36

physical properties of metals

Answer 36

``` shiny solids high melting points high density good electrical conductors malleable ```

Question 37

why are metals malleable

Answer 37

layers of pure metal can slide over one another

Question 38

what are the 4 kind of models

Answer 38

2D representations dot and cross 3D models ball and stick models

Question 39

evaluate 2d representations (2+, 2-)

Answer 39

simple and great shows how atoms are connected don't show shape of substance no indication of atom size

Question 40

evaluate dot and cross models

Answer 40

shows how compounds are formed shows where electrons/ions came from no indication of atom size no indication of atom arrangement

Question 41

evaluate 3d models

Answer 41

shows arrangement of ions only shows the outer layer of a substance

Question 42

evaluate ball and stick models

Answer 42

shows how the atoms are connected good for visualising structures makes it look like there are large gaps between atoms doesn't show correct scales of atoms or ions