Question

which of the elements are nonmetals? manganese iodine mercury carbon silicon boron selenium

Explanation:

To determine nonmetals, we recall: Nonmetals are elements that lack metallic properties.

• Manganese (Mn) is a metal (transition metal).
• Iodine (I) is a nonmetal (halogen, non - metallic properties like poor conductivity, brittle in solid form).
• Mercury (Hg) is a metal (liquid metal at room temp).
• Carbon (C) is a nonmetal (forms covalent bonds, non - metallic structure).
• Silicon (Si) is a metalloid (has properties of both, but often grouped with nonmetals in some contexts, but more accurately a metalloid; however, in basic classification, sometimes considered with nonmetals for simplicity here? Wait, no, strict nonmetals: Carbon, Iodine, Selenium. Wait, Silicon is a metalloid, Boron is a metalloid. Let's correct:

Nonmetals among these: Iodine (halogen, nonmetal), Carbon (nonmetal, in group 14, non - metallic), Selenium (nonmetal, chalcogen). Manganese: metal, Mercury: metal, Silicon: metalloid, Boron: metalloid. So the nonmetals are iodine, carbon, selenium.

Answer:

iodine, carbon, selenium (the checkboxes for these elements should be selected)