Consider the statements: I. Bond length in N+2 is greater than in N2. II. Bond length in NO+ is less than in NO. III. O2+ has a shorter bond length than O2. Which of the following statements are true?

Let's analyze each statement:

I. Bond length in N+2 is greater than in N2.
N2 has a triple bond (bond order = 3). N+2 has a bond order of 2.5. A higher bond order means a shorter bond length. Therefore, N2 has a shorter bond length than N+2. Statement I is true.

II. Bond length in NO+ is less than in NO.
NO has a bond order of 2.5. NO+ has a bond order of 3. A higher bond order means a shorter bond length. Therefore, NO+ has a shorter bond length than NO. Statement II is true.

III. O2+ has a shorter bond length than O2.
O2 has a bond order of 2. O2+ has a bond order of 2.5. A higher bond order means a shorter bond length. Therefore, O2+ has a shorter bond length than O2. Statement III is true.

Therefore, statements I, II, and III are all true.