Question

-Briefly explain how each of the following concepts is used in developing electron configuration of atoms:

a) the aufbau principle

b) Hund’s rule

c) Pauli Exclusion principle. 

-Write the electron configurations for each of the following atoms in the format specified below:

a. Complete configuration for Ni atom in its ground state

b. Complete configuration for one of the excited state of Si atom How many unpaired electrons are there in Ni atom?

-Give the orbital diagram just for the valence electrons of Antinomy Atom

-There is an expectation that element 126 might be stable enough to be synthesized and characterized. Predict and write the condensed electron configuration of this element.

Answer 1

1)

aufbau principle:

According to it the electron can occupy the lowest energy orbital first.

b) Hund’s rule

every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied, and all electrons in singly occupied orbitals have the same spin.

c) Pauli Exclusion principle

The Pauli Exclusion Principle states that, in an atom or molecule, no two electrons can have the same four electronic quantum numbers.

the two electrons in the same orbital can varies at spin quantum number.

2)

a) Ni: = [Ar] 4s²3d⁸

b)

Si⁺² = 1s² 2s² 2p⁶ 3s²

there are 2 un paired electrons in Ni atom

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Condensed electronic configuration of atomic no.of 126 element

= [Uuo] 8s² 7d⁶

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     Sb = [kr]5s² 4d¹⁰ 5p³