Question

which of these elements has the smallest atomic number?
zr (zirconium)
mn (manganese)
pt (platinium)
po (polonium)
which set contains a metalloid?
li, fe, o, ne
in, ti, i, xe
pb, er, cl, he
h, sb, tc, c

Explanation:

For the first question, atomic numbers: Zr=40, Mn=25, Pt=78, Po=84. Mn has the smallest. For the second, metalloids include Sb; the set H, Sb, Tc, C contains Sb.

Answer:

Mn (manganese)
H, Sb, Tc, C