January 14th

Today in class we did an experiment about Halogens. Halogens are the non-metals in the 17th group of the period table. They consist of Fluorine, Chlorine, Bromide, Iodine, and Astatine. They are very reactive because they have 7 valence electrons, therefore to have a full octet they only need one electron. Reactiveness decreases down a group, therefore Fluorine in the most reactive element in group 17. This is because as the atoms go down a group more electrons are added to the element so the atomic radius increases. So the pull from the protons is weaker, therefore they react less.

During our experiment we were reacting Halogens with other Halogens that were bonded with Potassium. We found that the more reactive Halogens replaced the less reactive Halogens in the potassium solution.  In our experiment we tested this by reacting Iodine, Chlorine, or Bromine Potassium solution with Iodine, Chlorine or Bromine. If there was a reaction we could deduce that the stronger Halogen had replaced the weaker Halogen in the potassium solution. For example, 

2KBr (aq) + Cl2  = 2 KCl (aq) + Br2 

We can see there that the Chlorine oxides or displaced the Bromine because it was more reactive.