Problem
Determine the chemical formula for nitrogen monoxide using the rules for naming binary molecular (covalent) compounds of nonmetals.
Key idea: prefixes in the name become subscripts in the formula
For binary molecular compounds, the name uses Greek prefixes to indicate how many atoms of each element are present. The compound nitrogen monoxide contains only nitrogen and oxygen, both nonmetals, so the prefix system applies.
Direct answer: The chemical formula for nitrogen monoxide is \( \mathrm{NO} \).
Step-by-step derivation of \( \mathrm{NO} \)
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Identify the elements in order. The name lists nitrogen first and oxygen second. In covalent naming, the first element keeps its element name; the second ends with “-ide” (oxide for oxygen).
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Read the oxygen count from “monoxide”. The prefix mono- means 1, so “monoxide” indicates one oxygen atom: \( \mathrm{O}_1 \).
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Infer the nitrogen count. No prefix appears on “nitrogen.” In standard covalent naming, omission of a prefix on the first element implies one nitrogen atom: \( \mathrm{N}_1 \).
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Write the formula without the subscript 1. Combine the element symbols in the stated order: \( \mathrm{N}_1\mathrm{O}_1 \rightarrow \mathrm{NO} \).
Common prefixes reference
| Prefix | Number of atoms | Example pattern |
|---|---|---|
| mono- | 1 | monoxide \(\rightarrow\) \( \mathrm{O}_1 \) |
| di- | 2 | dioxide \(\rightarrow\) \( \mathrm{O}_2 \) |
| tri- | 3 | trioxide \(\rightarrow\) \( \mathrm{O}_3 \) |
| tetra- | 4 | tetraoxide \(\rightarrow\) \( \mathrm{O}_4 \) |
| penta- | 5 | pentaoxide \(\rightarrow\) \( \mathrm{O}_5 \) |
Visualization: name-to-formula mapping for nitrogen monoxide
No prefix on first element \(\rightarrow\) count = 1
mono- \(\rightarrow\) 1 oxygen; oxide \(\rightarrow\) O
omit subscript 1
Common confusion to avoid
Nitrogen monoxide is \( \mathrm{NO} \). It is different from:
- nitrogen dioxide: \( \mathrm{NO}_2 \) (dioxide means 2 oxygens)
- dinitrogen monoxide: \( \mathrm{N}_2\mathrm{O} \) (di- on nitrogen means 2 nitrogens; still “monoxide” means 1 oxygen)
Final result
The chemical formula for nitrogen monoxide is \( \mathrm{NO} \).