group 7 - halogens Flashcards
the halogens exist as..
diatomic molecules
what state are halogens in at room temp?
gas
fluorine colour?
pale yellow
chlorine colour?
pale green
bromine colour?
red/brown
iodine colour?
grey (solid)
purple (gas)
state what is menat by displacement reaction
when a more reactive substance replaces a less reactive substance during a chemical reaction
reactivity of halogens
as you go down the group, the reactivity decreases.
how do the booling points of the halogens change down the group from fluorine to iodine?
the boiling point increases.
halogens ___ in size down the group
increase
how many more electrons do halogens need to gain to become stable?
- they have 7 electrons on the outer shell, so by gaining one more they become stable.
define ‘electrostatic attraction’
affected by the distance between two oppositely charged particles.
as you go down the group, reactivity ___. when the group 7 elements react, they ___ 1 outer electron.
as you go down the group:
1. greater ___ between the nucleus and incoming electron.
therefore, there is ___ ___ between the nucleus and the incoming electronic as you go down the group. (more shells there are/more shielding between the nucleus and the outer electron)
1.decreases
2.gain
3.distance
4.less attraction
explain in terms of electronic structure, why fluorine is the most reactive element in group 7. (3)
•overall, as you go down the group, the reactivity increases.
•this is due to electrostatic attraction. •fluorine has the least number of outer shells in this group
•this means that there is a greater attraction between the nucleus and the gaining electron because fluorine needs to gain 1 electron for a full outer shell which makes it stable. •due to its low amount of shells shielding is prevented causing and increase in attraction and decrease in distance between the nucleus and incoming electron.
chemical properties of group 0
•have full outer shells
•they do not need to bond
•they can exist on their own and be monatomic
