Question

case 5. diatomic molecules
several common non - metal elements have basic units that are diatomic molecules. the name of the element refers to the diatomic molecule. for example, \hydrogen\ refers to h₂ and \oxygen\ refers to o₂. (if we mean the atom, we say atomic hydrogen or atomic oxygen). the common diatomic elements are the four halogens, oxygen, nitrogen, and hydrogen.
exercise: list the names and formulas of the 7 elements that exist as diatomic molecules:
exercise: write both the name and formulas (or symbols) of the gases in the following paragraph.
dry air contains about 79% nitrogen and 21% oxygen, with small amounts of carbon dioxide, neon, and argon. polluted air may contain small amounts of sulfur dioxide, sulfur trioxide, nitrogen dioxide, dinitrogen monoxide, chlorine, ammonia, methane, and carbon monoxide.
exercise: write the names of the compounds (or elements) in the following paragraph.
probably the most important element found uncombined in nature is o₂. o₂ is quite reactive, forming compounds with the halogens f₂, cl₂, br₂ and i₂. o₂ forms two compounds with h₂. following the usual rules of nomenclature, the most common oxide of hydrogen (h₂o) would be named dihydrogen monoxide. the other oxide of hydrogen is h₂o₂. o₂ forms a series of compounds with n₂, many of which are atmospheric pollutants, including no, n₂o, no₂, n₂o₄, n₂o₅.

Explanation:

Step1: List diatomic - element molecules

Hydrogen - $H_2$, Oxygen - $O_2$, Nitrogen - $N_2$, Fluorine - $F_2$, Chlorine - $Cl_2$, Bromine - $Br_2$, Iodine - $I_2$.

Step2: List gases in dry and polluted air

Nitrogen - $N_2$, Oxygen - $O_2$, Carbon dioxide - $CO_2$, Neon - $Ne$, Argon - $Ar$, Sulfur dioxide - $SO_2$, Sulfur trioxide - $SO_3$, Nitrogen dioxide - $NO_2$, Dinitrogen monoxide - $N_2O$, Chlorine - $Cl_2$, Ammonia - $NH_3$, Methane - $CH_4$, Carbon monoxide - $CO$.

Step3: List compounds/elements in third - paragraph

Oxygen - $O_2$, Fluorine - $F_2$, Chlorine - $Cl_2$, Bromine - $Br_2$, Iodine - $I_2$, Hydrogen - $H_2$, Water - $H_2O$, Hydrogen peroxide - $H_2O_2$, Nitrogen - $N_2$, Nitric oxide - $NO$, Dinitrogen monoxide - $N_2O$, Nitrogen dioxide - $NO_2$, Dinitrogen tetroxide - $N_2O_4$, Dinitrogen pentoxide - $N_2O_5$.

Answer:

1. Diatomic elements: Hydrogen ($H_2$), Oxygen ($O_2$), Nitrogen ($N_2$), Fluorine ($F_2$), Chlorine ($Cl_2$), Bromine ($Br_2$), Iodine ($I_2$)
2. Gases in air: Nitrogen ($N_2$), Oxygen ($O_2$), Carbon dioxide ($CO_2$), Neon ($Ne$), Argon ($Ar$), Sulfur dioxide ($SO_2$), Sulfur trioxide ($SO_3$), Nitrogen dioxide ($NO_2$), Dinitrogen monoxide ($N_2O$), Chlorine ($Cl_2$), Ammonia ($NH_3$), Methane ($CH_4$), Carbon monoxide ($CO$)
3. Compounds/elements: Oxygen ($O_2$), Fluorine ($F_2$), Chlorine ($Cl_2$), Bromine ($Br_2$), Iodine ($I_2$), Hydrogen ($H_2$), Water ($H_2O$), Hydrogen peroxide ($H_2O_2$), Nitrogen ($N_2$), Nitric oxide ($NO$), Dinitrogen monoxide ($N_2O$), Nitrogen dioxide ($NO_2$), Dinitrogen tetroxide ($N_2O_4$), Dinitrogen pentoxide ($N_2O_5$)