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Name: Kelly
Status: student
Grade: 9-12
Location: VA
Country: USA
Date: Summer 2013

I'm doing a Biology project about water sanitation. One of the methods we used was iodine tablets- I know that iodine is highly reactive, but what allows the element/the tablet to serve as an antiseptic and to clean water? How exactly does it kill bacteria, and are there certain types of bacteria that it cannot kill?

Hi Kelly,

Thanks for the question. Iodine is an oxidizing agent which means that it takes two electrons from another molecule. When those two electrons are taken, it causes the molecule to fall apart. And if that molecule is part of a bacteria or virus, the bacteria could die or the virus could be incapacitated. As with all water treatment methods, none of the methods is 100% effective against all bacteria. In the instance of iodine, you would have to add a lot of iodine to make sure that all the bacteria would be killed. However, this amount of iodine would most likely cause ill effects in your digestive system.

I hope this helps. Please let me know if you have more questions. Thanks Jeff

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