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Ch.9 - Periodic Properties of the Elements

Chapter 9, Problem 22

Which of the transition elements in the first transition series have anomalous electron configurations?

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Hello everyone. Today, we have the following problem name the transition metal or metals in the second transition series that deviate or deviates from the expected order of electron filling based on the off ball principle. So this off ball principle, let's recall that it states that electrons will occupy orbitals in increasing energy. So they will occupy orbitals from the lowest energy to highest for this problem. The transition metals in the second transition series, there are three molybdenum represented by mo there is palladium with the symbol of PD and then there is a silver with the symbol A G and these exhibit anomalous electron configurations due to the stability linked with completely filling or half filling their dub shells. So, or molybdenum abbreviated as mo the expected electron configuration, the expected noble gas will be the noble GS that directly precedes it, which will be krypton. So we put krypton in brackets and then we enter the five S orbital. So we have five S and in the D orbitals, if this were a normal electron or a normal element, that's maybe like magnesium or oxygen, we would consider this to be or D four, right? It would follow the natural order of things. However, the actual noble gas configuration is Krypton five S one. So it's Krypton five S 14 D five. And so why is there this, why is there this discrepancy? Well, Motum has a half filled four D sub shell with the or D five instead of the expected configuration causing it to have greater stability. Now, the same principle can be applied to palladium. Oh, so what the symbol of PD? Now the expected configuration expected noble gas configuration will be the noble gas that directly perceives it. And this will be the case for the rest of these elements such as the silver. So we have Krypton in brackets followed by five S two and then a four D eight. However, the actual noble gas configuration is Krypton RD 10. So what essentially happens here is that palladium, it is more stable if it has a completely filled four D subs shell with a four D 10 instead of the four D eight. And this once again increases its stability. And for our last element, silver with the symbol of A G, this has an expected nobles configuration of our Krypton in brackets followed by five S two RD nine. However, it actually has the noble gas configuration of krypton and brackets five S one or D 10. So as in the previous examples, rather than having a partially filled four D nine subs shell silver would be much more stable if it had a completely filled configuration such as the four D 10. And so essentially the extra the electron, which is not really extra, it is derived from the next highest energy orbital, which would be the five S in this situation. And for palladium, it's also the five S. And then with molybdenum, it is also the five S. And so with that, we have solved the problem overall, I hope this helped. And until next time.