Question #4321c
1 Answer
The electronic configuration of metals depend on the number of electrons in the inner shells of their atom. If the inner shell, usually the shell next to the valence shell, is not complete, it imparts instability to the valence shell. What happens is the possibility of inner electrons jumping to the valence shell or vice versa. These metals frequently belong to the transition/inner transition metal groups.
Take the case of Cu whose electronic charges may range from +1 or +2. If we will locate Cu in the periodic table, its atomic number (Number of electrons) would be: 29. If we try and construct its electronic configuration by distributing the electrons, we would come up with: 1s =2;
2s=2;2p=6;
3s=2; 3p=6; 3d=9
4s=2.
Note that energy level 1 is filled to capacity and has 2 electrons. Energy level 2 has 8, its maximum number. Energy level 3 has 17 but its maximum capacity is 18. However, even if level 3 is not yet filled up, level 4 is already filling up, following the Aufbau order of filling up orbitals. This would result to a Cu = +2 with a inner shell configuration of 3s=2, 3p=6, 3d=9.
However, there is now the possibility of an electron jumping from the valence shell to the inner shell = Cu +1, with a inner and valence shell configuration of 3s=2, 3p=6, 3d=10 and 4s=1.
Hope this helps!
