please make sure that you know what affects the first ionisation energy of an atom
shielding (decreases) , distance ( decrease) and proton number (increases)
and the size of and atom or ion
proton number, shielding, and distance
make sure that you know how the periodic table is divided in to S,P ,D blocks - this tells you where the outer elctrons lie in the atom and where these blocks are located on the periodic table
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Atomic radii
across a period they will decrease because the proton number is getting higher , this pulls electrons in very storngly, but the shielding is staying the same making the atom smaller
down a group they will be bigger as you increase the number of electrons so much that you need another shell of electrons shielding increases and distance has too
distance is the over riding factor of what elffects the size of atoms
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first ionisation energy
the greater the distance/ or shielding the lower the first ionisation energy is , the greater the proton number there is an increase in the first ionisation energy
First ionisation energy will effect the type of bonding which an element will be able to take part in , the only types of bonding present in the Periodic table itself are covalent and metallic for diatoms etc
make sure that you know definitions of the different types of bonding that can happen
the general trend in ionisation energies in group 2 and 3 is an increase , i also shows periodicity as does melting point
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melting point
the pattern is low high low and this again goes for both groups
these trends come about becuase of the types of bonding in the 2 periods changing from metallic to covalent
it increases to start because of the metal bonding getting stronger because of the ions being formed getting smaller and the charges getting greater as well as a lower distance between the electrons and nucleus
however when the bonding type is no longer metallic you get covalently bonded elements which have weak forces of attraction between them and these are the ones yo break when the substance is heated not the covalent ones this explains why you get water vapour not H and O
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