In atomic physics and quantum chemistry, the distribution of electrons from an atom or molecule (or other physical structure) into atomic or molecular orbitals is the electron configuration. An orbital diagram helps to determine an element’s electron structure. The structure of the electrons in the shells is an element’s electron configuration.
Table of Contents
- What is Electronic Configuration?
- Recommended Videos
- Electronic Configuration of Iron
- Electronic Configuration of Copper
- Electronic Configuration of Chromium
- Electronic Configuration of Manganese
- Electronic Configuration of Oxygen
- Electronic Configuration of Sodium
- Frequently Asked Questions on Electronic Configuration of Elements
What is Electronic Configuration?
The organisation of electrons at different energy levels around an atomic nucleus is an electronic configuration, often called an electronic structure.
The distribution of electrons in various molecular orbitals in a molecule is called the electronic configuration. From the electronic configuration of a molecule or a molecular ion, it is possible to find out the number of electrons in bonding molecular orbitals and in antibonding molecular orbitals.
Recommended Videos
Electronic Configuration of Iron
Iron is a unique element , which is around and inside us . It has 8 valence electrons ( 4s23d6 ) and electron configuration 1s2 2s2 2p6 3s2 3p6 4s2 3d6 , meaning that iron has K – shell – 2 electrons L – shell – 8 electrons , M – shell – 14 and N – shell 2 electrons. Under regular conditions iron is a silvery whitre metal, ductile and easily malleable. Iron is a metal with medium activity it forces hydrogen from water solutions of such strong acids as HCl and sulphuric acid forming salts with iron.
Electronic Configuration of Copper
The electronic configuration of copper is [Ar] 3d104s1,. Compared to Group IA and IIA ions, copper ( II ) is essentially a soft cation with strong Lewis acid characteristics. In case of Cu ( Z = 29 ) the outer electronic configuration is [Ar]3d¹⁰4s¹ instead of [Ar]3d94s2. This is because half-filled and completely filled configurations are more stable. Common oxidation states of copper are +1 and +2.
Electronic Configuration of Chromium
Chromium is a transition element with the symbol Cr and atomic number 24.The electronic configuration can be written as 1s2 2s2 2p6 3s2 3p6 4s1 3d5 or [Ar] 4s1 3d5. Exceptional configuration is observed here as a half-filled configuration is more stable. The most common oxidation states of chromium are +6, +3, and +2.
Electronic Configuration of Manganese
Manganese is a transition element which is considered an essential nutrient because the body requires it to function properly. It has the atomic number 25.The electronic configuration can be written as 1s2 2s2 2p6 3s2 3p6 4s2 3d5 or [Ar] 4s2 3d5. In its compounds, manganese exhibits oxidation states from +2 to +7. The common oxidation states are +2, +4, and +7, but the less common +3, +5, and +6 states are easily prepared.
Electronic Configuration of Oxygen
Oxygen requires two additional electrons to achieve a full valence shell. These electronic configurations represent the most stable way of distributing those electrons already present in the atoms of these two elements. Oxygen has the electronic configuration [He] 2s²2p⁴. It is the most electronegative element of its family, therefore it takes up two electrons to acquire the nearest inert gas configuration and there are no d – orbitals for the excitation of electrons.
Electronic Configuration of Sodium
Sodium s an alkali metal with atomic number 11. The 11 electrons are distributed with 2 electrons in the K shell, 8 electrons in the L shell and 1 electron in the M shell . The M shell in this example is the valence shell. Electronic configurations of all the elements of a period are different, but all the elements of a period have the same number of energy shells in their atoms. For example, in the third period, the electronic configuration of sodium is 2,8,1 and that of chlorine is 2,8,7. Hence number of energy states are equal in both. All elements belonging to the same group as Na, have one electron in their valence shell.
Frequently Asked Questions on Electronic Configuration of Elements
What is the difference between Na+ and Na?
Na contains 11 electrons, while there are 10 electrons in Na+. Na is the symbol of a typical sodium atom with 11 protons in the nucleus, with a complete electrical structure of 11 electrons in all three shells (2,8,1). This is why the natural atom (Na) of sodium is electrically neutral. Yet Na+ is a sodium-positive ion.
How many electrons does the third shell consist of, 8 or 18?
The third shell of an atom comprises just 18 electrons, not 8 electrons. You may be surprised since the 4-s electrons are filled first and then the 10 3-d shell electrons are filled. Owing to the n+l law, they are filled. The maximum number of electrons in a shell is 2n2. So, 3rd shell contains 18 electrons as there are s,p and d subshells in 3rd shell.
Why is the electronic configuration of chromium different?
There are two major reasons: the 3d orbital is marginally lower in energy, and by transferring one of the 4s electrons to a close-lying 3d orbital, reducing repulsions in the 4s orbital minimises the chromium ground-state energy. The second reason is half filled configurations are more stable.
Is it easier to remove an electron from sodium or aluminium?
Na has one valence electron in 3s subshell which can be easily removed so that Na+ attains stable noble gas configuration . Aluminium has 3 valence electrons and its less easy to remove one electron compared to sodium.
Which is more stable O2 or O2+?
O2 + is steadier than O2–. Reason: O2 + has 15 electrons according to molecular orbital theory & it has one electron in the antibonding orbital. The molecule remains unstable if the number of electrons in the antibonding orbital is higher.
Comments