Bond length = b

Length of 10 atom chain = 9b

Length of 6 atom chain = 5b

The ground state configuration of the 10 electrons is:

Therefore the lowest energy transition is from n = 5 to n = 6. |

The ground state configuration of the 6 electrons is:

Therefore the lowest energy transition is from n = 3 to n = 4. |

Divide DE_{6} by DE_{10}