Answer: Option (a) is the correct answer.
Explanation:
Poly means many and polyatomic ions means an ion(s) with two or more different atoms.
Out of the given options, phosphate ion is the polyatomic ion which has an ionic charge of 3-.
The formula depicting a phosphate ion is .
Whereas Nitrate, Sulfate, Hydroxide
, Bicarbonate does not carry or have a 3- ionic charge.
Do you have Answer Choices
I would say C is the most correct.
In D it depends on what water source you're using. Let's say it is a waterfall, then the source of the water (melting ice or a lake) may disappear in the future.
If you're using underwater "windmills" placed in the ocean, then you would expect it to last a while as the ocean will not disappear in the near future.