The species CO, CN–and N2are:(a) isoelectronic(b) having coordinated bond(c)having polar bond(d) having low bond energies

The correct answer is (a) isoelectronic.

Here's the step by step explanation:

1. Isoelectronic species are atoms, ions or molecules that have the same number of electrons.

2. CO (Carbon Monoxide) has 10 electrons, CN- (Cyanide ion) has 10 electrons, and N2 (Nitrogen molecule) has 10 electrons. Therefore, they are isoelectronic.

3. A coordinated bond, also known as a dative bond, is a special type of covalent bond where the shared pair of electrons is contributed by one atom only. While CO and CN- do have a coordinate bond, N2 does not. Therefore, option (b) is not correct for all three species.

4. A polar bond is a covalent bond between two atoms where the electrons forming the bond are unequally distributed. This causes the molecule to have a slight electrical dipole moment where one end is slightly positive and the other is slightly negative. CO and CN- are polar, but N2 is not because it is a homonuclear diatomic molecule, so option (c) is not correct for all three species.

5. Bond energy is the amount of energy required to break one mole of a bond in a substance to produce separate atoms, everything being in the gaseous state. The bond energies of CO, CN-, and N2 are not particularly low, so option (d) is not correct.