1. Chemsheets AS006 (Electron arrangement)
30/04/2018
GROUP 7 – PHYSICAL PROPERTIES

2. F2
yellow gas
very reactive
toxic

3. Cl2
green gas
very reactive
toxic

4. orange liquid
very reactive
toxic
often used as a solution in water - bromine water, Br2(aq)
Br2

5. I2 grey crystals reactive toxic
easily turns into purple vapour on heating i.e. sublimes
used in solution as antiseptic
grey crystals
reactive
toxic I2

6. ATOMIC RADIUS F Cl Br I At

7. more electron shells
so bigger atoms
Increased shielding of inner shells

8. ELECTRONEGATIVITY REMEMBER//
Electronegativity is the ability of an atom to attract electrons when in a covalent bond

9. ELECTRONEGATIVITY
POWER OF AN ATOM TO ATTRACT THE 2 ELECTRONS IN A COVALENT BOND
F is the most electronegative atom since it has the smallest radius
Therefore attracts the bonding electrons strongly

10. MELTING & BOILING POINTS
bigger molecules  more van der Waals’ forces between the molecules  higher mpt/bpt

11. GAS I2 I I I I
SOLID I2
LIQUID I2 I I I I I I I I

12. All halogens form simple molecular structures.
There are weak VDW`s forces between the molecules which are easily overcome by heating

13. 1st IONISATION ENERGY atoms get bigger down the group more shielding
therefore weaker attraction from nucleus to electron in outer shell