Explain the rule according to which electrons are filled in various energy levels.
Explain the rule according to which electrons are filled in various energy levels.
Rules according to which electrons are filled in various energy levels were given by Bohr-Bury and known as Bohr-Bury scheme:
(1) The electrons are filled in various energy levels in the order of their increasing energy. i.e.; the energy level with the lowest energy is filled first and so on. The energy level closest to the nucleus is filled first because it has the lowest energy and the outermost level is filled the last as it has the highest energy.
(2) The maximum number of electrons that can be accommodated in an energy level is 2n2 where n= serial number of orbit and its value can be 1,2,…etc. Example: For first energy level or shell, n=1 and maximum number of electrons than can be accommodated in it are 2(1)2 i.e.; 2.
(3) New orbits are filled once the previous shells are completely filled. Sequential filling of orbits takes place. Example: Electronic configuration of Magnesium (Atomic number=12) is 2, 8, 2 instead of 2, 6, 4 because 2nd shell has to be fully filled before next orbit begins to accommodate electrons.
(4) The outermost orbit or energy level can accommodate a maximum of 8 electrons.
Example:
Electronic configuration of Argon (Ar) is 2, 8, 8. First and second energy level accommodates 2, 8 electrons respectively according to Bohr- Bury scheme.
According to point (3), the first and second shell is filled completely and then 3rd level is filled. i.e.; 2, 8, 8 and not 1, 8 as 2nd level is fully filled without completely filling first level.
According to point (4), the outermost level also has a maximum of 8 electrons.
Rules according to which electrons are filled in various energy levels were given by Bohr-Bury and known as Bohr-Bury scheme:
(1) The electrons are filled in various energy levels in the order of their increasing energy. i.e.; the energy level with the lowest energy is filled first and so on. The energy level closest to the nucleus is filled first because it has the lowest energy and the outermost level is filled the last as it has the highest energy.
(2) The maximum number of electrons that can be accommodated in an energy level is 2n2 where n= serial number of orbit and its value can be 1,2,…etc. Example: For first energy level or shell, n=1 and maximum number of electrons than can be accommodated in it are 2(1)2 i.e.; 2.
(3) New orbits are filled once the previous shells are completely filled. Sequential filling of orbits takes place. Example: Electronic configuration of Magnesium (Atomic number=12) is 2, 8, 2 instead of 2, 6, 4 because 2nd shell has to be fully filled before next orbit begins to accommodate electrons.
(4) The outermost orbit or energy level can accommodate a maximum of 8 electrons.
Example:
Electronic configuration of Argon (Ar) is 2, 8, 8. First and second energy level accommodates 2, 8 electrons respectively according to Bohr- Bury scheme.
According to point (3), the first and second shell is filled completely and then 3rd level is filled. i.e.; 2, 8, 8 and not 1, 8 as 2nd level is fully filled without completely filling first level.
According to point (4), the outermost level also has a maximum of 8 electrons.
