You have just been handed three sealed flasks. One smells like a swimming pool, one looks like blood, and one grows purple smoke when heated. Welcome to Group 17.
The Fume Cupboard
All three halogens are toxic. In a real lab, these would be handled exclusively inside a fume cupboard. Click to explore each one. Heat iodine to witness sublimation.
Cl₂
Chlorine
Br₂
Bromine
I₂
Iodine
Chlorine Cl₂
State at r.t.p.
Gas (g)
Cambridge Color
Pale yellow-green
Boiling Point
-34°C
Density
3.17 g/dm³
A toxic, choking gas used in WWI. Today it purifies water.
⚠️ EXAMINER TRAP
NEVER write 'yellow' alone. It must be PALE yellow-green.
🚨 HAZARD
TOXIC — Fume cupboard only. Attacks the respiratory system.