Covalent bonding

Question 1

what is covalent bonding

Answer 1

when two or more non metal aotms share electrons and form covalent bonds

Question 2

what are discrete covalent molecules

Answer 2

covalent molecular substances (water, Co2, Cl2…)

the bonds within these molecules (intra) are strong but the bond between the molecules (inter) are weak

Question 3

properties of covalent molecules

Answer 3

low Mp and Bp
dont conduct electricity
form soft solids
tend to be malleable instead of shattering
variable solubility

Question 4

why do covalent molecules have low mp and low bp

Answer 4

as teh forces that hold the molecules together are weak (inter is weak)

Question 5

why do covalent molecuels not conduct electricity

Answer 5

there are no charged particels that can move through the substnace

Question 6

why do covalent molecuels form soft solids

Answer 6

the forces that hold the molecules together are weak

Question 7

why do covalent moleucels tend to be malleable instead of shattering

Answer 7

the forces between the molecules are weak so the molecules cna easily be moved

Question 8

why do covalent substances have variable solubility

Answer 8

solubitliy depends on the forces between teh molecules (intermolecules forces)

Question 9

what are molecular solids

Answer 9

substances that contain discrete covalent molecules that are solid at room temperature

Question 10

what are properties of molecular solids

Answer 10

low mp and bp
soft/brittle - shatter when hit
cannot conduct electricity

Question 11

why do molecular solids have their propertei

Answer 11

teh weak force of attraction between teh molecules can be broken with a small amout of energy - Low mp and bp and soft/brittle

molecular solids are also unable to conduct electricity as there are no free electrons or ions to carry a charge

Question 12

what is a covalent network

Answer 12

when covalent bonds in substances do not form discrete molecules but vast networks of atoms

its a large 3D network of covalently bonded atoms with a very strong intermolecular force that is basically a covalent bond

Question 13

proeprteis of covalent network

Answer 13

very high Mp Bp
do not conduct electricity
extremely hard and brittle
insoluble in water and most solvens

Question 14

why do covalent networks have high mp and bp

Answer 14

covalent bonds that hold the atoms together are strong

Question 15

why do covalent networks have do not condcut electricity

Answer 15

no charged particles that can move through the structure

Question 16

why do covalent networks have hard and brittle

Answer 16

bonds are very strong between atoms but an impact force disrupts positions of atoms and cause networks to shatter

Question 17

why do covalent networks have insoluble in water and most solvenets

Answer 17

no attraction between atoms in network and water molecules

Question 18

what are allotropes

Answer 18

different forms of teh same elemtn (graphite andd diamond)

carbon allotropes

Question 19

propeteis of diamond

Answer 19

hard, high mp and bp and cannot conduct electricity

Question 20

properties of graphite

Answer 20

soft and slippery and conducts electricity

Question 21

why is graphite soft and slippery and cant conduct electricity

Answer 21

layers can easily slide over each other due to weak forces of attraction are easily broken which is why it’s used as a lubricant

free electron from each carbon means that each layer has delocalised electrons that can carry a charge