Write orbital configuration of 3d series element with symbolic representation and explain
Answers
Answer:
Explanation:
The purpose of introducing quantum numbers has been to show that similarities in the electron arrangement or electron configuration lead to the similarities and differences in the properties of elements. But writing the quantum numbers of electrons of an element in set notation like {2,1,-1,1⁄2} is time consuming and difficult to compare so an abbreviated form was developed. An electron configuration lists only the first two quantum numbers, n and ℓ , and then shows how many electrons exist in each orbital. For example, write the electron configuration of scandium, Sc: 1s2 2s2 2p6 3s2 3p6 4s2 3d1 . So for scandium the 1st and 2nd electron must be in 1s orbital, the 3rd and 4th in the 2s, the 5th through 10th in the 2p orbitals, etc.
electron_config_memory.png
This is a memory device to remember the order of orbitals for the first two quantum numbers. Follow the arrow starting in the upper right, when the arrow ends go to the next arrow and start again.
In Scandium, the 4s has lower energy and appears before 3d (the complexity of the d-orbitals leads to its higher energy), so it is written before adding 3d to the electron configuration. But it is common to to keep all the principle quantum numbers together so you may see the electron configuration written as Sc: 1s2 2s2 2p6 3s2 3p6 4s2 3d1. Writing electron configurations like this can cause difficulties in determining the element that matches an electron configuration. But if you just count the number of electrons it will equal the number of protons which equals the atomic number which is unique for each element. For example: “Which element has the electron configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d104s24p6 4d8 5s2 ?” Counting the electrons gives 46, which is the atomic number of palladium.
Here’s a diagram of the first several electron configurations. David’s Whizzy Periodic Table is a visual way of looking at the changing electron configuration of elements.
Ptable_e_configs.png
Note the 3d orbital follows the 4s in the lowest row, but starting with Ga (#31) it is next to the 3p orbital. It is most commonly listed with the other 3 orbitals, but sometimes it follows the 4s orbital to indicate that the 3d orbital is lower in energy than the 4s while it is being filled.
Periodic Table Exceptions To Know
There is a major exception to the normal order of electron configuration at Cr (#24) and Cu (#29). It turns out that the energy the electron configuration that is half-filled, 4s1 3d5 , and filled orbital, 4s1 3d10 , has lower energy than the typical filling order, 4s2 3d4 , and 4s2 3d9 . This pattern is followed in the 5th row with Mo (#42) and Ag (#47).
f block
Elements For completeness a couple of f-block elements are listed here. Neodymium, Nd, which is used in very powerful magnets, has an atomic number of 60. For 60 electrons the electron configuration is:
1s2 2s2 2p6 3s2 3p6 4s2 3d104s24p6 4d105s25p66s24f4
For californium, Cf, with 98 electrons the electron configuration is:
1s2 2s2 2p6 3s2 3p6 4s2 3d104s24p6 4d105s25p66s24f145d106p67s25f10