Asked in ETEA MDCAT 2015 2015Moderate

Stable electronic configuration of Cu(29) is:

Correct answer: C. [Ar] 4S1 3d10

  • A. [Ar] 4S2 3d4
  • B. [Ar] 4S0 3d10
  • C. [Ar] 4S1 3d10
  • D. [Ar] 4S2 3d7 4p2

Explanation

It is a transition element. Copper (Cu) is a chemical element, a reddish, extremely ductile metal of Group 11 (IB) of the periodic table that is an unusually good conductor of electricity and heat. Due to the interelectronic repulsions one electron present in 4s enters to 3d subshell. We can write a stable electronic configuration of copper is written as 1s22s22p63s23p63d104s1. There is additional stability because of the completely occupied 3d subshell and half-filled 4s subshell.orThe electronic configurations of copper (and chromium) are unique since without filling the 4s orbitals, electrons entered into 3-d orbitals. Copper has an atomic number of 29 hence 29 electrons are fulfilled by option C as well.

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