@Why is chlorine added to water in swimming pools
Disinfect the water
As a bleach
To soften the water

@Which of the following is incorrect for the halogens?
They are all gases at room temperature
They are all oxidising agents
Usually form negative ions

@Which one of the following is a liquid at room temperature?
Bromine
Iodine
Fluorine

@The substance used to kill bacteria in tap water is:
Chlorine
Ammonia
Bromine

@Which of the following is a chemical symbol for a halogen?
I
He
Na

@Which of the following is a possible source for bromine?
Sea water
Bauxite
Haemetite

@For chlorine gas, which of the following is incorrect?
It is lighter than air
It is soluble in water
It is dangerous to inhale

@Which one of the following is a solid at room temperature (20C)?
Iodine
Bromine
Chlorine

@What will displace bromine from sodium bromide solution?
Chlorine gas
Aqueous iodine
Aqueous potassium iodide

@When it is heated, iodine sublimes. This means it:
Goes straight from a solid to a vapour
Changes colour on heating
Gives off a toxic vapour