Chemistry: The Halogens

Group 7 = 7 electrons in the outer shell. 

• They are all non-metals. 
• They are all diatomic = molecules of two atoms. 
• F2 not F, Cl2 not Cl, etc. 
• They are all toxic vapors. i.e. they are poisonous. 
• Fluorine, Chlorine, Bromine, iodine, astatine. 
• Fluorine is a yellow gas. 
• Chlorine is a green gas.
• Bromine is a dark red liquid. 
• Iodine is a dark grey solid or a purple vapor. 
• Astatine is probably  black - but…