The species CO, CN–and N2are:

The species CO (Carbon Monoxide), CN- (Cyanide ion), and N2 (Nitrogen molecule) are all examples of diatomic molecules.

Here's the step by step explanation:

1. Diatomic molecules are molecules composed of only two atoms, of the same or different chemical elements.

2. CO (Carbon Monoxide) is a diatomic molecule composed of one carbon atom and one oxygen atom.

3. CN- (Cyanide ion) is a diatomic molecule composed of one carbon atom and one nitrogen atom. It carries a negative charge because it has one extra electron.

4. N2 (Nitrogen molecule) is a diatomic molecule composed of two nitrogen atoms.

5. Therefore, all three species CO, CN-, and N2 are diatomic molecules.