group 7 Flashcards
fluorine
pale yellow gas
chlorine
yellow green gas
bromine
dark red brown liquid
iodine
grey black solid
astatine
black solid
bonding and structure
covalent bonding and elements exist as diatomic molecules with simple covalent structure
physical properties
low melting and boiling points so little energy is needed to break the weak london forces between molecules
melting and boiling point increases down the group
increase in melting and boiling point down the group because
more shells so more electrons
more london forces between molecules
more energy is required to break the london forces between molecules
group 7 elements are powerful
oxidising agents as they remove electrons from another species so get reduced themselves
reactivity in group 7
decreases down the group and oxidising power also decreases as you go down
more shells and atomic radius increases
greater shielding effect by inner shell electrons
weaker nuclear attraction on the outer shell electrons
nucleus is less able to attract and capture another electron into its outer shell
example of redox reaction
displacement
displacement reaction
reaction in which a more reactive element displaces a less reactive element from an aqueous solution of its halide ions
displaced halogen
has its own colour so its easy to detect if a displacement reaction has occurred
dissolved in water
Cl2
Br2
I2
dissolved in water
pale green
orange
brown
dissolved in organic solvent
Cl2
Br2
I2
dissolved in organic solvent
pale green
orange
purple
