Because compounds have properties that are VERY different from the elements that make them up. Sodium is extremely reactive; chlorine is toxic, but put them together and you get relatively harmless sodium chloride, or table salt.
There are other examples as well: hydrogen is highly flammable and oxygen supports combustion, but put them together and you get water, which is neither flammable nor supportive of combustion.
I hope that helps. Good luck!
There are other examples as well: hydrogen is highly flammable and oxygen supports combustion, but put them together and you get water, which is neither flammable nor supportive of combustion.
I hope that helps. Good luck!
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Lucas got most of it. Sodium is ~especially~ reactive, as is chlorine. When they react with each other they bond so tightly that very little will pull them apart, which makes for a very stable, non-reactive and usually not very toxic compound. It takes fluorine to snatch the chlorine ion away from sodium, and nothing else will do it.