Ohio Assessment for Educators (OAE) Integrated Science (024) Practice Exam

What is the chemical formula for nitride?

1. N2-

2. N3-

3. N^-3

4. NO3-

The correct answer is: N^-3

The chemical formula for nitride is represented by N^-3. This notation signifies that a nitride ion consists of a nitrogen atom that has gained three electrons, resulting in a negative charge of three. In ionic compounds, nitrogen typically forms nitride ions when it combines with metals or forms part of a compound with a positive charge, such as in metal nitrides. The presence of the three negative charges indicates that nitride has a high tendency to form ionic bonds, as it seeks to achieve stability by gaining electrons. Other options do not represent nitride correctly; for instance, N2- and N3- suggest different oxidation states or bonding scenarios not applicable to nitride in its typical ion form. NO3- represents the nitrate ion, which contains both nitrogen and oxygen and is not a simple nitride. Thus, N^-3 accurately indicates the natures of a nitride ion.