Why iron in Total cereal can be detected by a magnet, as well as merits of iron and drawbacks of too much iron

Funded in part by a Science Education Partnership Award (SEPA) (Grant #: 1R25RR024279-01A1)
from the National Center for Research Resources (NCRR) at the National Institutes of Health (NIH)
and by an undergraduate science education award from the Howard Hughes Medical Institute