Hey there! We receieved your request
Stay Tuned as we are going to contact you within 1 Hour
One of our academic counsellors will contact you within 1 working day.
Click to Chat
1800-5470-145
+91 7353221155
Use Coupon: CART20 and get 20% off on all online Study Material
Complete Your Registration (Step 2 of 2 )
Sit and relax as our customer representative will contact you within 1 business day
OTP to be sent to Change
There are 2parts of this matter,one is why the oxidation state has not been higher,and the other is why it is not lower than +3.
The absence of higher states than 3+ for the Lanthanides is mainly due to the much greater stabilisation of the 4f orbitals compared to 5d and 6s.The order of penetration of the orbitals into the inner electron core is 4f>5d>6s. So the 4f eletrons are the closest to nucleus and attracted by it the most.Now,as successive ionisation increases the net charge on the lanthanide cation,being closest to the nucleus,4f electrons are pulled even more closer than 5d and 6s electrons. Thus is Ln3+,4f electrons are just too strongly pulled by the nucleus to be ionised further as it will requirea huge energy for it. So states higher than +3 is generally not seen.
Ce and Pr are exceptional as they are at the beginning of the series,so the effective nuclear charge is not so high to be able to attract the 4f electrons much more than 5d and 6s.Tb+4 is stable because of having a fully filled 4f shell.
There could have been lower oxidation states,but that doesn't happen due to the lower hydration energy of +2 cations compared to +3 ions due to +2 cations having a lower charge density.Here,also exceptions are present like Eu+2 and Yb+2,which is due to the +2 state having a half filled and a fully filled 4f level respectively.
Get your questions answered by the expert for free
You will get reply from our expert in sometime.
We will notify you when Our expert answers your question. To View your Question
Win Gift vouchers upto Rs 500/-
Register Yourself for a FREE Demo Class by Top IITians & Medical Experts Today !