Electronic Configuration of Elements

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.

What is Electronic Configuration?

The organisation of electrons at 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. It is important about the molecule. 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 ( II ) is  [Ar] 3d¹⁰4s¹, which is far removed from a noble gas configuration . Compared to Group IA and IIA ions , copper ( II ) is essentially a soft cation with strong Lewis acid characteristics. Consider the outer electronic configuration of Cr ( Z = 24 ) , which is [Ar] 3d⁵ 4s¹ instead of [Ar] 3d4 4s2 ( auf bau principle ) . Similarly , in case of Cu ( Z = 29 ) the outer electronic configuration is [Ar]3d¹⁰4s¹ instead of [Ar]3d94s2 .

Electronic Configuration of Chromium

All chromium nuclei have charge +24 electronic units, so that 24 electrons orbit the nucleus of the neutral atom. Cr is [Ar] 3d⁵ 4s¹ not [Ar] 3d4 4s2; Cu is [Ar] 3d¹⁰4s¹ not [Ar] 3d94s2. Unpredicted electron configurations also occur with silver and gold, elements that are in the same group as copper. The process of filling up of subshells goes on successively till nickel with Z = 28 except in the case of Cr where the electronic configuration is 1s22s22p63s23p64s13d5 with the electronic ground state as “S.

Electronic Configuration of Manganese

The outer electron configuration of Mn is e The transition elements can lose up to three electrons to form positive [Ar] 3d5 4s2 . It uses the two 4s electrons in ions , e . g , M+, M2+ and M3+ , but the higher the number of electrons. The organisation of electrons at energy levels around an atomic nucleus is an electronic configuration, often called an electronic structure.

Manganese has an atomic number 25, meaning 25 protons in its nuclei are in its atoms. Even, a neutral atom of manganese has 25 electrons. The electron structure for a neutral Mn atom is [Ar] 3d5 4s2 in noble gas shorthand. For a Mn3 + ion, the electron structure is [Ar]3d4.

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 takes up two electrons to acquire nearest inert gas configuration and there are no d – orbitals for excitation of electrons.

Electronic Configuration of Sodium

Sodium ( Z = 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 energy states are equal in both.

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.

Why is 3rd shell 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. So the next shell to fill after loading the 3s and 3p subshell with 8 electrons is the 4s one.

Why is the electronic configuration of chromium?

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.

Is it easier to remove an electron from sodium or aluminum?

To form a Na+ ion with a filled-shell electron structure, it doesn’t take much energy to detach one electron from a sodium atom. The second aluminium ionisation energy is greater than the first, and the third aluminium ionisation energy is much higher.

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.

Test your knowledge on Electron Configuration Chart

Leave a Comment

Your Mobile number and Email id will not be published. Required fields are marked *




Free Class