2 b Group 7 Flashcards
2.5 - 2.8
Why do halogens rarely occur naturally
Theyre very reactive
What are the gases in gr 7
-Fluorine
-Chlorine
What is the liquid in gr 7
-Bromine
Physical properties of gr 7
-Soft when solid
-Poor conductors
-Low melting & boiling points
-Dissolve in water
Describe the trends going down group 7
-Relative atomic mass increases
-Colour becomes darker
-Melting & boiling points increase
-Reactivity decreases
Why does the reactivity decrease as you go down gr 7
Halides have to attract electrons to form a reaction. As you go down the group, the size increases, and the outer shell (-) is further from the nucleus (+), so due to the distance its more difficult to attract electrons
All halogens exist as what
Diatomic molecules. Strong bonds, weak forces of attraction
What is reduction
Gain of electrons
What is oxidation
Lose of electrons
Colours of gr 7 at room temp.
-Fluorine
-Chlorine
-Bromine
-Iodine
-Yellow
-Green
-Red-brown
-Grey, purple vapour
