I've seen various different periodic tables that call selenium a nonmetal and a semimetal. Which one is correct?

The units of resistivity don't come out right.

10^-8 Ohm * m
or
m Ohm * cm

the 'm' should be a 'mu', but unfortunately they both look the same in the latin alphabet.

Brazil nuts have been promoted as a supplement to a healthy diet since the late 1970’s. This is due to their unusually high selenium content, an essential trace element known to be a powerful antioxidant and to reduce the likelihood of conditions such as heart disease and prostate cancer.

Recent research by Ryszard Lobinski and colleagues at the University of Pau and the Adour (France) has shown that the selenium compounds contained in Brazil nuts are seleno-peptides, and have developed a new method for their extraction, purification and characterisation. This has led to the discovery of 15 new seleno-peptides. Their research should help us to understand why Brazil nuts are so good at accumulating selenium.