Name: Basics of Relative Atomic Mass
Uploaded: 2019-07-19
Duration: 4 min 23 s
Description: Relative atomic mass is a tricky concept that's actually quite simple to understand. Here, you will know how to calculate it. Find out more in this video!

Question

In many textbooks the electronic configuration for vanadium is written as

[Ar] 4 s^{2} 3 d^{3}

. This is common practice and widely accepted by the chemical community. However, suggest why this way of writing the electronic configuration for vanadium may be at odds with experimental evidence.

Accepted Answer

The plot of orbital energy (E) vs. atomic number (Z) for neutral atoms is shown below:

When comes to the ionisation energies for this element, the $4 s$ electrons as the outer electrons and are shielded from the nucleus by the inner $3 d$ levels. So that the first ionization energies do not change much across the transition series, because each additional $3 d$ electron screens the $4 s$ electrons from the nucleus. According to ionisation energies $4 s$ electrons having the higher energy, so removed first, when the atom undergoes ionisation.The explanations around ionization energies are based on the $4 s$
electrons having the higher energy, and so being removed first.

In vanadium, $3 d$ electrons having the lower orbital energy than 4s electrons, so the $3 d$ subshell should be filled before the $4 s$ subshell, however, the formula $[Ar] 4 s^{2} 3 d^{3}$ gives the reverse order of orbital energies, i.e. $energy of 4 s < energy of 3 d$ , this is opposite to the experimental evidence, so the better representation of vanadium electron configuration is $[Ar] 3 d^{3} 4 s^{2}$ , to avoid odds with experimental evidence.

In many textbooks the electronic configuration for vanadium is written as $[Ar] 4 s^{2} 3 d^{3}$ . This is common practice and widely accepted by the chemical community. However, suggest why this way of writing the electronic configuration for vanadium may be at odds with experimental evidence.

Important Questions on Atomic Structure

Learn and Prepare for any exam you want !

In many textbooks the electronic configuration for vanadium is written as Ar4s23d3. This is common practice and widely accepted by the chemical community. However, suggest why this way of writing the electronic configuration for vanadium may be at odds with experimental evidence.

Important Questions on Atomic Structure

Learn and Prepare for any exam you want !

In many textbooks the electronic configuration for vanadium is written as $[Ar] 4 s^{2} 3 d^{3}$ . This is common practice and widely accepted by the chemical community. However, suggest why this way of writing the electronic configuration for vanadium may be at odds with experimental evidence.