Where are all metalloid found in this periodic table?

What’s the percent by mass of carbon in c10h14n2

Which is a chemical property of iron? a. it forms iron oxide (rust) when exposed to moisture and air. b. it is a gray–black metal that is hard to the touch. c. it has a melting point of 2795°f (1536°c). d. it is a good conductor of heat

Chen drew a diagram to compare the ways in which different organisms obtain nitrogen. which label belongs to the area marked z?