Question

question 6 of 25
why are prefixes used in naming covalent compounds?
a. the prefixes identify the only way the atoms can combine.
b. the atoms can have different numbers of valence electrons.
c. the same atoms can combine in more than one ratio.
d. oxidation states of the atoms are identified with prefixes.

Explanation:

• Option A: Atoms can combine in multiple ways, not just one, so this is incorrect.
• Option B: Valence electrons determine bonding capacity, not the need for prefixes in covalent naming. This is irrelevant to the use of prefixes.
• Option C: In covalent compounds, the same elements can form compounds with different atom ratios (e.g., CO and CO₂). Prefixes (mono-, di-, tri- etc.) are used to indicate the number of each atom, so this explains why prefixes are needed.
• Option D: Oxidation states are indicated by Roman numerals in ionic compounds (for transition metals), not by prefixes in covalent naming.

Answer:

C. The same atoms can combine in more than one ratio.