Chlorine and bromine are in Group 7 of the periodic table. Give one similarity and one difference between the electronic structures of a chlorine atom and a bromine atom.

A halogen displacement reaction occurs when a more reactive halogen displaces a less reactive halide ion from its solution.

Which combination of mixtures will produce a displacement reaction when mixed?

• Iodine and sodium bromide solution
• Bromine and sodium chloride solution
• Chlorine and sodium iodide solution
• Iodine and sodium chloride solution

Which of the following describes the trends observed when moving down Group 7?

• Atomic radius increases and reactivity decreases.
• Atomic radius increases and reactivity increases.
• Atomic radius decreases and reactivity decreases.
• Atomic radius decreases and reactivity increases.