Final answer:
An excited state configuration for lithium could be 1s²2p¹, showing that the electron from the 2s orbital has moved to the 2p orbital after absorbing energy.
Step-by-step explanation:
The main answer to the question regarding which electron configuration represents an atom of lithium in an excited state involves understanding that in an excited state, electrons have absorbed energy and have moved to a higher energy orbital than their ground state. For lithium, the ground state electron configuration is 1s²2s¹. In an excited state, the remaining electron from the 2s orbital may have jumped to the 2p orbital or even higher, such as 3s, depending on the amount of energy absorbed. A possible excited state configuration for lithium could thus be 1s²2p¹, indicating that the third electron has moved from the 2s to the 2p orbital.