In a compound formed from two non-metals, how are oxidation numbers assigned?

In a compound formed from two non-metals, how are oxidation numbers assigned?

• A. The less electronegative element gets the negative sign
• B. The more electronegative element gets the positive sign
• C. The more electronegative element gets the negative sign
• D. Both have zero

Answer: (C)

In compounds formed from two non-metals, oxidation numbers are assigned by looking at how electrons are shared in the bond. The more electronegative element pulls the bonding electrons toward itself, so when we assign oxidation numbers we pretend those electrons wholely belong to that element. That element therefore gets a negative oxidation state, while the less electronegative element gets a positive one. For a neutral compound, the total of these oxidation numbers must add to zero, so the numbers balance. This rule fits real examples: in carbon dioxide, oxygen is more electronegative than carbon, so each oxygen is assigned -2 and carbon must be +4 to balance to zero. In hydrochloric acid, chlorine is more electronegative than hydrogen, so chlorine is -1 and hydrogen is +1. The statement that the more electronegative element gets the negative sign is the correct description of how oxidation numbers are assigned in two-non-metal compounds.

In compounds formed from two non-metals, oxidation numbers are assigned by looking at how electrons are shared in the bond. The more electronegative element pulls the bonding electrons toward itself, so when we assign oxidation numbers we pretend those electrons wholely belong to that element. That element therefore gets a negative oxidation state, while the less electronegative element gets a positive one. For a neutral compound, the total of these oxidation numbers must add to zero, so the numbers balance.

This rule fits real examples: in carbon dioxide, oxygen is more electronegative than carbon, so each oxygen is assigned -2 and carbon must be +4 to balance to zero. In hydrochloric acid, chlorine is more electronegative than hydrogen, so chlorine is -1 and hydrogen is +1. The statement that the more electronegative element gets the negative sign is the correct description of how oxidation numbers are assigned in two-non-metal compounds.