MCAT Physical : Electron Configuration
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Example Questions
Example Question #49 : Nuclear Chemistry And Electrons
An electron in which of the following orbitals is closest to the nucleus?
Nuclear orbitals will always fill from the innermost to the outermost subshells. Using the 
5s and 3d produce the same number from the 
Example Question #831 : Mcat Physical Sciences
What is the electron configuration of Fe+?
When an element loses an electron it is generally taken away from the highest electron shell. The electron configuration of iron (Fe) is 
Example Question #841 : Mcat Physical Sciences
Which of the following is the correct electronic configuration for vanadium?
[Ar]3d34s2
[Ar]3d24s2
[Ar]4s24p3
[Ar]3d44s1
[Ar]3d34s2
When determining electronic configuration, the answer is made much easier by starting with the next smallest noble gas in brackets. As a result, [Ar] is an appropriate way to incorporate every previous electron before argon.
After argon, vanadium has five other electrons to distribute, and because vanadium is a transitional element, it will fill its 3d subshells before filling the 4p subshells. The 4s subshell is filled first, and the last three electrons are placed into the 3d subshells.
[Ar]3d34s2
Example Question #14 : Electron Configuration
Which of the following is the correct notation for a sodium ion?
A neutral atom of sodium would contain eleven electrons to balance out the charge of the eleven protons in the nucleus. We are asked, however, for the configuration of a sodium ion. Sodium is an alkali metal, meaning that it will ionize by losing only one electron, gaining a charge of 
Neutral sodium:
Sodium ion:
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