Bonding and structure; covalent bonds

Question 1

what are molecules formed from

Answer 1

2 or more atoms that bond togther whic could be the same or different.

Question 2

what is covalent bonding?

Answer 2

-sharing of electrons
-between NON-metals
-electrostatic forces of attraction between shared pair electrons and postive nucleus.

Question 3

what else is there between the postitve nuclei in covalent bonding + state why?

Answer 3

repulsion due to two positive nucleis–> to maintain covalent bond–> balence forces with attraction and repulsion

Question 4

what are the physical properties of SIMPLE molecular covalent substances + what are they the opposite of?

Answer 4

OPPOSITE TO THE PHYSICAL PROPERTIES OF IONIC BONDING

-low mp==>little energy to ovecome the intermolecular forces between molecules–> weak compared to covalent bonds

-do not conduct electricity–>no charge carriers

-insoluble–> the water molecules are attracted to each other rather than the molecular substance

Question 5

how are the bonding electrons represented in covalent bonds?

Answer 5

they are drawn with their outer atomic orbitals overlapping

Question 6

for diatomic molecules how do you distinguish if there is a single double or triple bond?

Answer 6

you do 8 - the group number

Question 7

what is dative bonding?

Answer 7

-a type of covalent bond
-when an atom donates a pair of electrons to an atom or ion to form a bond

Question 8

how many dative and covalent bonds are shared in carbon monoxide?

Answer 8

2 covalent bonds and one dative bond

Question 9

what compounds are excepetions for the oct rule in covalent bonding?

Answer 9

boron trifluride AND sulfur hexafluride

Question 10

what are some examples of giant covalent strcutures?

Answer 10

-graphite
-diamond
-silicon dioxide

Question 11

what do giant covalent structures have?

Answer 11

a huge network of covalently bonded atoms (millions)

Question 12

how many carbons is graphite bonded to?

Answer 12

3 carbons and one delocalised electron

Question 13

does graphite have a high or low mp and why?

Answer 13

high mp–>lots of strong covalent bonds within graphene

Question 14

do the layers slide easily or not in graphite and why?

Answer 14

a
yes because of the weak intermolecular forces between the layers of graphene

Question 15

does graphite conduct electricity and why?

Answer 15

yes due to the 4th electron being delocalised –> carries charge

Question 16

does graphite have a low or high density and why?

Answer 16

low density due to length of the layers in comparison to length of covalent bonds

Question 17

is graphite souluble or insoluble and why?

Answer 17

insolouble–> covalent bonds are too strong to break

Question 18

how many times is carbon bonded in diamond?

Answer 18

4 times

Question 19

does diamond conduct heat and why ?

Answer 19

yes–> due to the tight packed rigid arrangement of aroms

Question 20

is diamond hard or soft and what can it do?

Answer 20

diamond is hard –>could be used to cut gemstones

Question 21

does diamond have a low or high mp and why?

Answer 21

a
high mp–>due to the very strong covalent bonds

Question 22

does diamond conduct electricity and why?

Answer 22

no as there is no delocalised electrons to carry charge

Question 23

is diamond soluble or insolouble and why?

Answer 23

insolouble–> coavalent bonds are too strong to break