This problem is asking for the theoretical effective nuclear charge for sodium and a reason behind its difference with the actual one. At the end, the answers are 1+ and because the 3s¹ electron has a small probability of being closer to the nucleus.
In chemistry, the effective nuclear charge is defined as the net positive charge valence electrons experience. In addition, one can approximate it with the equation:
Zeff = Z – S
Where Z is the atomic number or number of electrons and S the core electrons.
In such a way, since sodium has 11 electrons and 10 core electrons due to its electron configuration (1s²2s²2p⁶3s¹), one concludes its effective nuclear charge is:
Zeff = 11 - 10 = +1
On the other hand, since the actual effective nuclear charge has a value of about 2.667, one concludes this difference is due to the fact that the 3s¹ electron has a small tendency of being closer to the nucleus and therefore, there is a likelihood that this electron undergoes a greater attraction in comparison to the proposed in the theoretical model.
Learn more about effective nuclear charges: https://brainly.com/question/6965287
Answer:
At first glance, we expect the Zeff of sodium (Z = 11) to be 1 , but in reality, it is closer to 2.667 because the assumptions that 1) core electrons block protons 1 for 1 and 2) valence electrons don't block at all are not completely valid..
Explanation:
At first glance, we expect the Z_eff of sodium (Z = 11) to be 1, but in reality, it is closer to 2.667 because the assumptions that core electrons shield protons 1 for 1 and valence electrons do not shield are not completely valid.
In the case of sodium (Na) atom, a valence electron is presenting 3s-orbital and the total number of shielding electrons is 10. Thus, the expected Ze must be equal to 1. The net charge (an effective nuclear charge (Z_eff) is a charge that experience by a valence electron which not only depends upon the charge on the nucleus but also the screening effect of the inner electron
