Hund S Rule Of Electronic Configuration
In atomic physics hund s rules refers to a set of rules that german physicist friedrich hund formulated around 1927 which are used to determine the term symbol that corresponds to the ground state of a multi electron atom.
Hund s rule of electronic configuration. When we draw electrons we use up and down arrows. This chemistry video explains what is the aufbau s principle hund s rule and pauli s exclusion principle and how it relates to orbital diagrams electron c.
All alpha electrons or all beta electrons. Electrons tend to minimize repulsion by occupying their own orbitals rather than sharing an orbital with another electron.
S orbitals can hold two electrons and p orbital holds 2 electrons by following hund s rule of highest multiplicity. It says if two or more than two orbitals having the same amount of energy are unoccupied then the electrons will start occupying them individually before they fill them in pairs.
Furthermore the most stable configuration results when the spins are parallel i e. The electrons have opposite spins.
The multiplicity is equal to 2 s 1 displaystyle 2s. The rule states that for a stated electron configuration the greatest value of spin multiplicity has the lowest energy term.
In other words the under subshell should have maximum multiplicity. Therefore no two electrons in the same atom can have the same set of four quantum numbers.
The first rule is especially important in chemistry where it is often referred to simply as hund s rule. The rule discovered by friedrich.
Same n and l quantum numbers they must first occupy the empty orbitals before double occupying them. Hund s rule of maximum multiplicity this rule deals with the filling of electrons in the equal energy degenerate orbitals of the same sub shell p d and f.
For a given electron configuration the term with maximum multiplicity has the lowest energy. Hund s rule explained according to the first rule electrons always enter an empty orbital before they pair up.
Total no of 6 electrons is disposed over 1s 2s and 2p orbitals. Electrons must spin in opposite directions.
The rule states that for a given electron configuration the lowest energy term is the one with the greatest value of spin multiplicity. According to this rule electron pairing in p d and f orbitals cannot occur until each orbital of a given sub shell contains one electron each or is singly occupied.
So if an electron is paired up in a box one arrow is up and the second must be down. Hund s rule states that when electrons occupy degenerate orbitals i e.
Hund s rule of maximum multiplicity is a rule based on observation of atomic spectra which is used to predict the ground state of an atom or molecule with one or more open electronic shells. This implies that if two or more orbitals of equal energy are available electrons will occupy them singly before filling them in pairs.
The electron configuration for carbon atom is recorded as. According to this principle for a given electronic configuration the paring of the particle is done after each subshell is filled with a single electron.
