![Page 1: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/1.jpg)
Can you draw Bohr diagrams for flourine and chlorine onto your
worksheet?
![Page 2: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/2.jpg)
Group 7 – the halogensThe elements in group 7 of the periodic table, on the right, are called the halogens.
fluorine
chlorine
bromine
iodine
astatine
I
Br
Cl
F
At
![Page 3: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/3.jpg)
Halogens – what do they look like?
Chlorine Bromine
Iodine
![Page 4: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/4.jpg)
Halogen vapoursBromine and iodine are not gaseous, but have low boiling points. This means that they produce vapour at relatively low temperature. They are volatile.
Bromine produces some red-brown vapour, seen here above the liquid bromine in the jar.
When iodine is heated gently, it changes directly from a solid to a gas without first becoming a liquid.
This is called sublimation.
![Page 5: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/5.jpg)
How does electron structure affect reactivity?The reactivity of halogens decreases going down the group. What is the reason for this?
The atoms of each element get larger going down the group.
This means that the outer shell gets further away from the nucleus and is shielded by more electron shells.
The further the outer shell is from the positive attraction of the nucleus, the harder it is to attract another electron to complete the outer shell.
This is why the reactivity of the halogens decreases going down group 7.
decr
ease
in re
activ
ity
F
Cl
![Page 6: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/6.jpg)
How do halogen molecules exist?All halogen atoms require one more electron to obtain a full outer shell and become stable.
Each atom can achieve this by sharing one electron with another atom to form a single covalent bond.
This means that all halogens exist as diatomic molecules:F2, Cl2, Br2 and I2.
+ F F F F
![Page 7: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/7.jpg)
Halogens in competition
Chlorine is more reactive than iodine or bromine. It can “push” (displace) bromine or iodine out of solution.
Cl2(aq) + 2KBr(aq) 2KCl(aq) + Br2(aq)
![Page 8: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/8.jpg)
Halogens in competition
Chlorine is more reactive than iodine or bromine. It can “push” (displace) bromine or iodine out of solution.
Cl2(aq) + 2KBr(aq) 2KCl(aq) + Br2(aq)
![Page 9: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/9.jpg)
Let’s have a look at some demonstrations of halogens
![Page 10: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/10.jpg)
Starter
• As a group you have 5 min to ‘act out’ a displacement reaction of a halogen and it’s corresponding halide.
• Bonus points for using actual names of the elements/chemicals involved
![Page 11: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/11.jpg)
Halogens in competition
Chlorine is more reactive than iodine or bromine. It can “push” (displace) bromine or iodine out of solution.
Cl2(aq) + 2KBr(aq) 2KCl(aq) + Br2(aq)
![Page 12: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/12.jpg)
Halogens in competition
Chlorine is more reactive than iodine or bromine. It can “push” (displace) bromine or iodine out of solution.
Cl2(aq) + 2KBr(aq) 2KCl(aq) + Br2(aq)
![Page 13: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/13.jpg)
Tasks for this lesson:1. Carry out the practical detailed on your
‘Reactions of the halogens’ sheet (1 per group)
2. On a separate sheet try and write word AND chemical equations for the displacement reactions that DID occur
3. As an extension try and BALANCE the equations
![Page 14: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/14.jpg)
Displacement reactions: summaryThe reactions between solutions of halogens and metal halides (salts) can be summarised in a table:
2KCl + I2
2KBr + I2
halogen
chlorine
bromine
iodine
salt (aq) potassiumchloride
potassiumiodide
potassiumbromide
2KCl + Br2
no reactionno reaction
no reaction
![Page 15: Can you draw Bohr diagrams for flourine and chlorine onto your worksheet?](https://reader036.vdocuments.mx/reader036/viewer/2022062504/5a4d1b287f8b9ab059997fdf/html5/thumbnails/15.jpg)
Displacement EquationsPotassium Bromide and Chlorine:• 2KBr + Cl2 2KCl + Br2
Potassium Iodide and Chlorine:• 2KI + Cl2 2KCl + I2
Potassium Iodide and Bromine:• 2KI + Br2 2KBr + I2