A teacher while explaining the definition of ionisationn potential gave an example: Ionisation potential value of sodium is 140 kJ// mol. That means, 140 kJ of energy is required to remove the lone electrons form '3s' orvitals of one mole of gaseous sodium atoms. Then, a student Rinku stood up immediately and asked: sodium is a solid metal. Why should we consider it in gaseous state? What explanation would have been given by the teacher?

A teacher while explaining the definition of ionisationn potential ga

1.	A teacher while explaining the definition of ionisationn potential gave an example: Ionisation potential value of sodium is 140 kJ// mol. That means, 140 kJ of energy is required to remove the lone electrons form '3s' orvitals of one mole of gaseous sodium atoms. Then, a student Rinku stood up immediately and asked: sodium is a solid metal. Why should we consider it in gaseous state? What explanation would have been given by the teacher?
Answer» Solution :For any element. Ionisation potential is considered for gaseous state only. Ionisation potential corresponds to the energy required to overcome the electron WITHOUT considering any other kinds of attreactions. In gaseous state, the intermolecular FORCES of attractions being negligible, removal of electron from a neytrak gaseous atom involces an amount of energy equal to IP only. In solid and liquid states, the intermolecular forces of ATTRACTION are STRONGER ant the energy required to remove electron involves not only IP but also the energy required to overcome the other forces. Thus, for any element, IP is considered only for the isolated gaseous atoms irrespective of the state in which it EXISTS.