bonding topic (1st unit of year 10)

Question 1

ionic bond

Answer 1

positive and negative ions bonded together.

Question 2

metallic bond

Answer 2

attraction of positive ions in a regular lattice and delocalised electrons.

Question 3

covalent bond

Answer 3

when non- metals atoms bond together, they share a pair of electrons to make covalent bonds.

Question 4

why do metals form +ve ions

Answer 4

they are losing electrons (the number of electrons lost depends on their group number) to make the outer shell)

Question 5

why do non metals from -ve ions

Answer 5

they gain electrons to make a full outer shell (depending on their group number)

Question 6

why do ionic substances have a high mpt

Answer 6

strong electrostatic forces of attraction between positive ions and negative ions that require a lot of energy to overcome.

Question 7

one pair electron bond

Answer 7

single covalent

Question 8

two pair electron bond

Answer 8

double covalent

Question 9

what is a giant ionic lattice

Answer 9

lots of oppositely charged particles in a lattice structure with electrostatic forces of attraction that are strong and require a lot of energy to overcome as it has a high mpt. they are held together by ionic bonds

Question 10

why do ionic substances have to be molten in order to conduct electricity

Answer 10

this is because if they are in a solid state they are not free to move meaning they cannot carry a charge and so they need to be moving in order to carry a charge and conduct electricity.

Question 11

how do molecules form

Answer 11

through covalent bonding

Question 12

how are simple covalent molecules held together

Answer 12

the atoms of the molecule are held together by strong covalent bonds however there are very weak intermolecular forces which do not require a lot of energy to overcome which means they have a low mpt and bpt.

Question 13

how are giant covalent structures held together

Answer 13

made up of a huge number of atoms all joined by covalent bonds

Question 14

why can giant covalent molecules not conduct electricity

Answer 14

this is because they do not carry a charge even when molten.

Question 15

what is an electrostatic force

Answer 15

between oppositely charged particels

Question 16

what are intermolecular forces

Answer 16

the forces between molecules

Question 17

why cant simple covalent molecules not conduct electricity

Answer 17

this is because they do not have an overall electric charge.

Question 18

how are giant molecular substances arranged

Answer 18

regular repeating lattices

Question 19

why are giant covalent structures solid at room temperature

Answer 19

this is because they have millions of strong covalent bonds which means they have high mpt and bpt.

Question 20

what is diamond formed from

Answer 20

carbon

Question 21

how many covalent bonds does diamond form

Answer 21

4

Question 22

why does diamond have a high mpt and bpt

Answer 22

because it has millions of carbon atoms joined by covalent bonds which require a lot of energy to overcome

Question 23

why can diamond not conduct electricity

Answer 23

because it has no free electrons or ions .

Question 24

how many covalent bonds does graphite from

Answer 24

3

Question 25

what is the structure of graphite

Answer 25

sheets of carbon atoms arranged in layers

Question 26

explain graphite’s structure

Answer 26

there are no covalent bonds between the layers they are only held together weakly, this means they are free to move over each other which makes them soft and slippery.

Question 27

why has graphite got a high mpt

Answer 27

the covalent bonds in the layers need loads of energy to overcome.

Question 28

explain why graphite is conductive

Answer 28

delocalised electrons between the layers which are free to move

Question 29

when do ionic substances not conduct

Answer 29

when solid

Question 30

what is the structure of graphene

Answer 30

a single layer of graphite and it is very thin

Question 31

how many covalent bonds does graphene form

Answer 31

3

Question 32

what is graphene’s use

Answer 32

touch screen

Question 33

how many covalent bonds does nanotube form

Answer 33

3

Question 34

how many covalent bonds does fullerene form

Answer 34

3

Question 35

why does fullerene have a low mpt

Answer 35

weak intermolecular forces

Question 36

what is the structure of a metal

Answer 36

positive ions in a lattice structure surrounded by delocalised electrons

Question 37

why do metals have high mpt and bpt

Answer 37

this is because they have strong electrostatic forces between the positive ions and the delocalised electrons which results in strong metallic bonds that require a lot of energy to overcome.

Question 38

why are metals conductive

Answer 38

they have delocalised electrons which are free to move and carry a charge.

Question 39

explain why graphite is soft

Answer 39

because the layers of carbon slide over eachother

Question 40

why are metals malleable

Answer 40

because the layers of atoms in a metal can slide over eachother

Question 41

what do we do yo make pure metals stronger

Answer 41

mix them with other elements to make them harder

Question 41

what do we do yo make pure metals stronger

Answer 41

mix them with other elements to make them harder

Question 42

what happens when another element is mixed with a pure metal

Answer 42

the new atoms will distort the layers of the metal atoms making it more difficult for the layers to slide over each other.

Question 43

how do you melt or boil a simple molecular substance.

Answer 43

break the intermolecular forces not the covalent bonds

Question 44

what is the trend in mpt and bpt’s as a molecule gets bigger

Answer 44

increases as the intermolecular forces get stronger so it requires more energy to break them.

Question 45

what is a covalent bond ?

Answer 45

between two atoms or ions in which the electron pairs are shared between them