Science Buddies: "Ask an Expert"

My daughter is finishing her science fair project ( assessing which type of potato powers a clock longer) and we have been unable to find the phosphorus content of a purple potato. Can anyone help?

Hello,
There are many different varieties of purple potatoes, but the Okinawa sweet potato has 37 mg of phosphorus according to this website:http://www.livestrong.com/article/33866 ... nutrition/
This potato has lilac flesh and tan skin. It might not be the variety of potato you used in the experiment.

Thanks!