What element is not classified as a metal, nonmetal, or metalloid?

Boron and/or Polonium

Explanation:

In the periodic table, you can see a stair-stepped line starting at Boron (B), atomic number 5, and going all the way down to Polonium (Po), atomic number 84. Except for Germanium (Ge) and Antimony (Sb), all the elements to the left of that line can be classified as metals.

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