O S

O CN O
CH3CH2ONa
O
NH
SO2

O - Oxygen

CN - Cyanide
CH3CH2ONa - Sodium ethoxide
NH - Ammonia
SO2 - Sulfur dioxide

It seems you have provided a series of chemical compounds and symbols. To assist you, I will explain the steps involved in understanding these compounds.

1. O - The symbol "O" typically represents oxygen. Oxygen is a chemical element with the atomic number 8. It is often found in various chemical compounds, including organic and inorganic substances.

2. S - Similarly, the symbol "S" represents sulfur. Sulfur is a chemical element with the atomic number 16. It is widely used in various industrial applications and is frequently found in compounds such as sulfides, sulfates, and sulfuric acid.

3. O CN O - This compound consists of three elements: oxygen (O), carbon (C), and nitrogen (N). The specific structure or name of this compound cannot be determined without further information.

4. CH3CH2ONa - This compound is called sodium ethoxide. It comprises four elements: carbon (C), hydrogen (H), oxygen (O), and sodium (Na). Sodium ethoxide is an organic compound often used as a strong base and as a reagent in organic synthesis.

5. O - This symbol "O" represents oxygen, similar to the first point mentioned.

6. NH - The symbol "NH" suggests the presence of ammonia, which is a compound made up of nitrogen and hydrogen. Ammonia is a colorless gas with a pungent odor and is widely used as a cleaning agent and fertilizer.

7. SO2 - This compound is called sulfur dioxide, which consists of sulfur (S) and oxygen (O). Sulfur dioxide is a toxic gas formed during the combustion of sulfur-containing compounds and is a major contributor to air pollution.

Please note that the information provided here is a general explanation of the compounds based on the symbols and names you provided. For more specific details or further explanations, please provide additional context or ask more specific questions.

Based on the information you provided, it seems like you have a molecule with multiple elements such as Oxygen (O), Carbon (C), Hydrogen (H), Sodium (Na), and Nitrogen (N), and also a compound called sulfur dioxide (SO2). It's unclear what specific question you have related to these elements and compounds. Can you please provide more context or clarify your question? That way, I can provide you with a more detailed answer.