2.3 halogens Flashcards
what is fluorine?
very pale yellow gas. It is highly reactive
what is chlorine?
greenish, reactive gas, poisonous in high concentrations
what is bromine?
red liquid, that gives off dense brown/orange poisonous fumes
what is iodine?
shiny grey solid sublimes to purple gas.
what is the trend in melting and boiling point for the halogens?
increases down the group
why dos the trend for melting and boiling point increase down the group?
As the molecules become larger they have
more electrons and so have larger van der
waals forces between the molecules. As the
intermolecular forces get larger more energy
has to be put into break the forces. This
increases the melting and boiling points
what is the def for electronegativity?
electronegativity is the power of an atom to attract a pair of electrons towards itself in a covalent bond
what is a covalent bond?
a shared pair of electrons
what is the trend of electronegativity for the halogens?
As you go down the group the electronegativity of the
elements decreases.
what is the trend of atomic radii for the halogens?
how does this affect the nucleus?
As you go down the group the atomic radii increases due
to the increasing number of shells.
The nucleus is therefore
less able to attract the bonding pair of electrons.
what does a halogen with a strong oxidising agent do?
A halogen that is a strong oxidising agent will
displace a halogen that has a lower oxidising
power from one of its compounds.
what is the trend for oxidising strength?
The oxidising strength decreases down the group.
def for oxidising agents
oxidising agents are electron acceptors
does Cl displace Br and I?
Chlorine will displace both bromide and iodide ions
does Br displace I?
bromine will displace iodide ions
