Now look up the first ionization energies of Ge and As. Are there larger changes

Question

Now look up the first ionization energies of Ge and As. Are there larger changes on moving from the second period to the third (C rightarrow Si, N rightarrow P) or on moving from the third period to the fourth (A1 rightarrow Ga, Si rightarrow Ge)? Is this expected based on the simple trends taught in class? Discuss your answers to (a) and (b) in light of what Slater's Rules calculate: Calculate Eslater = -(Z*)2/(n*)2 for the outermost electron in C, Si, and Ge. In a sentence or two explain why moving from C to Si is different than moving from Si to Ge.

Explanation / Answer

Ionization energy is a periodic trend. It increases as you move across the table to the right. It also increases as you go up the table. Explanation as to why: Ionization energy is the energy required to remove the outermost electon from an atom. Elements such as the halogens (Flourine, Chlorine, Iodine, Bromine) want an extra electron to complete their full orbit. Because of this, they do not want to lose an electron, they want to gain it. This results in a high amount of energy to remove the electron. That explains why it increases as you go to the right. To explain why it increases as it goes up, you need to look at the number of electrons. As you go up the table you lose electron orbitals, thus making the electrons closer to the atom. Because the outermost electron is closer to the nucleus, the attraction between the protons and electrons are stronger. This is why as you go up the columns ionization energy increases. So to estimate the ionization of element 118 (I believe it is called Ununoctium) look at the plot and find the ionization of the elements that are to the right and left of it. I would estimate in between them. Note that there are SOME exceptions to this trend, this is just an overall pattern.

Related Questions

Navigate

• Browse (All)
• Browse N
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.