Question

carbon, helium, hydrogen, iodine, oxygen, sodium; diatomic element, monatomic element (table with two columns)

Explanation:

Step1: Recall diatomic/monatomic elements

Diatomic elements: $H_2$, $O_2$, $I_2$ (Hydrogen, Oxygen, Iodine).
Monatomic elements: Noble gases (He), metals (Na), non - metal solids (C) (Helium, Sodium, Carbon).

Step2: Classify each element

• Diatomic: Hydrogen ($H_2$), Iodine ($I_2$), Oxygen ($O_2$).
• Monatomic: Carbon (C, solid non - metal), Helium (He, noble gas), Sodium (Na, metal).

Answer:

Diatomic Element: hydrogen, iodine, oxygen
Monatomic Element: carbon, helium, sodium