group 7 non metals Flashcards
elements in group 7 are known as
halogens
halogens are
non metals which are poisonous
all halogens have similar reactions as
they have 7 electrons in their outmost shell
halogens are diatomic meaning
they form molecules made of pairs of atoms sharing electrons (forming a single covalent bond between the two halogen atoms)
colour and state of the halogens at room temp
Fluorine- Yellow gas
Chlorine- Pale yellow-green gas
Bromine- Red-brown liquid
lodine- Purple-black solid
the melting and boiling point of the halogens
increase as you go down - this is due to the increasing intermolecular forces as the atoms become larger, so more energy is required to overcome these forces
the halogens react with metals to become
ionic compounds which are metal halide salts
the halogens decrease in
reactivity as you move down the group, but they still form halide salts with some metals including iron
the rate of reaction is
slower for halogens which are further down the group such as bromine and iodine
the halogens react with
hydrogen to form hydrogen halides
reactivity decreases
down the group
fluorine is
the most reactive
a halogen displacement reaction occurs when
a more reactive halogen displaces a less reactive halogen from an aqueous solution of its halide
if you add chlorine solution to colourless potassium bromide or potassium iodine solution a
displacement reaction occurs- the solution becomes orange as bromine is formed or the solution goes brown as iodine is formed
chlorine is above bromine and iodine in group 7 so
its more reactive
