Bonding, structure and properties of matter

what is covalent bonding

• when non metal atoms bond together and share pairs of electrons

what kind of bond is between covalent bonding

strong bond

what are the 3 types of forms that bonding can be represented in

• energy level diagrams

• dot and cross diagram

• stick diagram

what are the molecules which have a ONE covalent bond

• hydrogen (H2O)

• chlorine (Cl2)

• hydrogen chloride (HCl)

what are the molecules which have a 2 or more covalent bonds

• water (H2O) = 2 CB

• ammonia (NH3) = 3 CB

• Methane (CH4) = 4 CB

what are the molecules which have more than a single covalent bond

• oxygen (O2) = double CB

• nitrogen (N2) = triple CB

what are the types of form diagrams that you must know p+ & n- for

• dot and cross

• ball and stick

• 2D stick D

• 3D stick D

• what are p & n for dot and cross

• + - clear on where electrons are coming from

• - does not show shape of molecule

what are n for 2D stick

• no shape of molecule

• doesnt show where what electron comes from which atom

what are p for 3D stick

• shape of molecule is shown

what are p & n for ball & stick

• p - clearly see ions in 3 dimensions

• n - ions shown spaced out = reality theyre packed together

what are the 3 giant covalent substan

what is diamond made of and how many covalent bonds included

• carbon atoms joined by covalent bonds in between = extremely hard

• 4 covalent bonds

what are the properties of diamond and why

• high melting and boiling points - to melt = takes lots of energy to break CB

• cannot conduct electricity = no free electrons to carry charge

• large repeating regular lattice

what atoms are silicon dioxide made of

• silicon and oxygen atoms covalently bonded together

what are the properties of silicon dioxide and how come?

• v higher melting & boiling point - to melt = break CB = takes lots of energy

what atoms is graphite made of and how many covalent bonds does it consist of

• carbon atoms

• 3 covalent bonds per carbon atom

what are the properties of graphite and why

• soft & slippery = no CB between layers = can slide over each other

• very high M & B points - melt =break SCB = lots of energy

• conductor of heat and electricity = 1 delocalised electron from each carbon atom which carry charge

what are fullerenes and graphene made of

carbon atoms

what are the properties of graphene

• one layer of graphite = 1 layer thick

• sheets folded into spheres and tubes

• good conductor of H & E - delocalised electrons = carry electrical charge

• high M & B points - melt = many strong CB = takes lots of energy to break

what are fullerenes and give an key example of one

• hollow shapes

• rings with 5-7 carbon atoms

• e.g buckministerfullerene

describe buckministerfullerene

• 60 carbon atoms arranged in a hollow sphere

• rings = 5-6 carbon atoms

what are the uses of buckministerfullerenes

• used to deliver drugs

• catalyst to speed up chemical reactions

• used as lubricants in machines = reduces friction

describe carbon nanotubes

• fullerenes shaped into long cylinders

• rings = 6 carbon rings

• high length to diameter ratios

what are the properties for nanotubes

• high tensile strength = apply lots of stretching force

• good conductor of H & E = delocalised electrons carry charge

what is a use for nanotubes

• reinforce materials

• e.g tennis rackets

• nanotechnology

what are polymers

• very large molecules made by joining up monomers

• polymer molecules linked to other atoms by strong covalent bonds

what are the properties of polymers

• solids at room temp = strong intermolecular forces of attraction between molecules = lots of energy to break in order for melting = higher M & B POINTS

WHAT are the key aspects of a polymer repeating unit that you must draw

• n = which represents a large number

• single line = single covalent bond

• lines must extend out of both brackets

what is it called when metals bond to other metals

metallic bonding

what do solid metals consist of

• giant structure of atoms in a regular pattern

what happens to atoms outer level electrons

• shared with other atoms = delocalised and creates sea of delocalised electrons

• metal which looses E = positive ion

how is metallic bonding created after

• strong electrostatic forces of attraction between negative E & positive metal ions in a metal

therefore , what are the properties of metals

• high M & B points = to melt = lots of energy to break metallic bonds

• good conductors of heat and electricity = delocalised elctrons carry charge and thermal energy

• malleable = layers of atoms slide over each other

what is an alloy

• mixture of metals

what is a property of alloys

• harder = made of diff size atoms = difficult for layers to slide over

what is ionic bonding

when non metal and metal atoms react , outer level ectrons of metal are transferred

why does ionic bonding take place

in order for atoms to gain full outer energy level like group 0

• what happens to group 1 metals during IB

• what happens to group 7 non metals during IB

• looses 1 electron and forms 1 positive ion

• gains 1 electron and forms 1 negative ion

what do groups 1 and 2 metals and group 6 and 7 have

• electronic structure of a noble gas