Slides in this set
Atomic radius and boiling
· The atoms get bigger as you go down the group
because the atomic no. increases so each element has
1 extra filled main level of electrons compared with
the 1 above it.
· Due to the fact the F atoms are so small, there is
repulsion between non bonding e¯ s. Therefore F-F is
weaker than expected. This leads to greater VDW
forces between molecules, increasing the energy
needed to separate the molecules and therefore have
higher melting and boiling points.…read more
Electronegativity is a measure of the
ability of an atom to attract an e¯.
Electronegativity of the halogens
decreases down the group due to an
increase in atomic radius.
Electronegativity depends on nuclear
charge and shielding .
Increased nuclear charge has no
significant effect because there are or
electron shells and more shielding. So
the shared e¯s are further from the
nucleus with an increase in shielding
from more inner shells.
Therefore I atoms attract e¯ in a
covalent bond less strongly than F
How do halogens usually
· By gaining e¯s to become ve ions
Cl+ 2e¯ 2Cl¯
· Halogens are good oxidising
agents, so they are reduced.
· An oxidising agent is an agent
that removes e¯s from another
·OIL --- OXIDATION IS LOSS
·RIG --- REDUCTION IS GAIN (OF ELECTRONS)…read more