chemistry paper 1- bonding Flashcards
what are ions
positively/negatively charged particles
what happens when metals form ion
lose electrons from their outer shell = positive ion
what happens when non-metals form ion
gain electrons into their outer shell = negative ion
group 1,2,6,7 form what type of ions?
Group 1 - 1+
Group 2 - 2+
Group 6 - 2-
Group 7 - 1-
what is the ionic bonding transfer of?
electrons = to do with metal an non-metal
What diagram is used for ionic bonding?
dot and cross diagram
Flaws and Benefits of dot and cross diagrams?
+ show how ionic compounds are formed
- doesn’t show the structure of it
- doesn’t show the size or how they’re arranged
Properties of a ionic compound?
giant ionic structure
ions are closely packed in a regular lattice structure
strong electrostatic forces of attraction between the oppositely charged ions
high mpt + bpt = strong bonds = lots of energy needed
what happens when a ionic compound is solid?
ions are held in place= don’t conduct electricity
when they melt= ions free to move = carry electric charge
What diagram is used for covalent bonding?
displayed formula + dot and cross
Properties of a covalent compound?
SHARING ELECTRONS (non-metals)
positively charged nuclei=electrostatic forces = strong bonds
can only share in their outer shell
what are simple molecular substances made out of ?
molecules made out of few atoms joined together by covalent bonds
Properties of a simple molecular substance?
very strong covalent bonds= weak forces of attraction = low mpt and bpt as they can easily part away from each other
what are polymers?
long chains of molecule that repeat
properties of a polymer?
large intermolecular forces so more energy needed to break it = solid at room temp
examples of giant covalent structures
diamond
graphite
silicon dioxide
what are allotropes ?
different structural forms of the same element
Diamond Properties?
strong covalent bonds= lots of energy to break = high mpt
does not conduct electricity= no free electrons
Graphite properties?
no covalent bonds between the layers
held weakly together so they slide over each other
soft and slippery
what are fullerenes?
molecules of carbon - shaped like closed tubed
form nanotubes = conduct electricity and heat
they have high tensile strength
what is metallic bonding?
metals- giant structures - very strong
have a sea of delocalised electron = strong electrostatic forces of attraction between the ions = good conductor of heat
high mpt and bpt
malleable
Alloys + Pure Metals
Alloys are harder and pure metals are softer as they only consist of one type of metal + alloys is a mixture
solids properties
strong forces of attraction= close together in fixed position
don’t move but they vibrate in their position
liquids properties
weak forces of attraction= they are free to move but stick closely together
don’t keep a shape but have volume
constantly moving particles
