the cobalt atom has how many unpaired electrons in its ground state?
2
4
1
0
3
To determine the number of unpaired electrons in the cobalt atom's ground state, we need to first know the electron configuration of cobalt.
The electron configuration of cobalt is [Ar] 3d^7 4s^2.
To find the number of unpaired electrons, we look at the orbital diagram of cobalt. The 3d subshell has a maximum capacity of 10 electrons, and the 4s subshell has a maximum capacity of 2 electrons.
In the ground state electron configuration, we distribute the electrons starting from the 1s orbital and fill up each subsequent orbital with the maximum number of electrons before moving onto the next orbital.
In the case of cobalt, since there are 7 electrons in the 3d subshell, and 4 of them will have opposite spins (paired), there will be 3 unpaired electrons in the 3d subshell. The 4s subshell is filled with 2 paired electrons.
Therefore, cobalt has 3 unpaired electrons in its ground state.
So, the correct answer is 3.
The cobalt atom has 3 unpaired electrons in its ground state.
The easy way to know the electronic structure for the 3d elements is to follow DrBob's rule. The number of electrons in the 3d orbtials for the 3d transition metals is the second number of the atomic number (EXCEPT for Cr and Cu).
For Co, atomic number 27, that means we have 7 electrons in the 3d orbitals. Since there are five such degenerate orbitals; therefore, draw five boxes in a line, put electrons into each box one at a time). When you have used five electrons you will have one electron in each box and the sixth electron MUST pair up with one already there. The second one MUST pair also. Thus we have left three electrons not paired.