[LHM]

Out of the following two, which one's the metalloid?

Element A: slight luster, high conductivity, bubbles slowly when reacted with HCl
Element B: shiny, low conductivity, no reaction when reacted with HCl

Most sources that I have found say that metalloid characteristics are between metals and nonmetals, but both elements seem to fit somewhere in between metals and nonmetals, so how do you tell which one is the metalloid?

[rabolisk]

Element B has lower conductivity and is not oxidized by HCl, both of which are properties of metals in general. So B is a metalloid.

[LHM]

So the one that's less like a metal is the metalloid? Do nonmetals typically behave more like nonmetals then?

[Borek]

Rabolisk answer is probably the one teacher wants, but in general this is a poor question. It can be that both elements are metalloids. There is a continuum of properties between metals and nonmetals, question would make sense if the classification was strict.

Perhaps stating "B is more metalloidal" would be the best