Write the full and abbreviated electron configurations for molybdenum: How many core and valence electrons does it have? A: 36;
The Correct Answer and Explanation is:
Molybdenum (Mo) has an atomic number of 42, which means it has 42 electrons. The electron configuration of molybdenum can be written in two forms: the full and the abbreviated forms.
Full Electron Configuration:
The full electron configuration for molybdenum is:
1s22s22p63s23p64s23d104p65s24d41s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^6 5s^2 4d^41s22s22p63s23p64s23d104p65s24d4
Abbreviated Electron Configuration:
To abbreviate the electron configuration, we use the noble gas that precedes molybdenum in the periodic table, which is Krypton (Kr) with an atomic number of 36. The abbreviated electron configuration is:
[Kr]5s24d4[Kr] 5s^2 4d^4[Kr]5s24d4
Core and Valence Electrons:
- Core Electrons: Core electrons are those that are in the inner energy levels and do not participate directly in chemical bonding. These are the electrons in the inner shells, and for molybdenum, these are the electrons that correspond to the configuration of the noble gas Kr.
- Core electrons: The configuration of Kr is [Kr]=1s22s22p63s23p64s23d104p6[Kr] = 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^6[Kr]=1s22s22p63s23p64s23d104p6, totaling 36 electrons.
- Therefore, molybdenum has 36 core electrons.
- Valence Electrons: Valence electrons are the outermost electrons involved in chemical bonding. For molybdenum, these are the electrons in the 5s and 4d orbitals.
- Valence electrons: 5s24d45s^2 4d^45s24d4, totaling 6 electrons.
- Therefore, molybdenum has 6 valence electrons.
Conclusion:
- Core electrons: 36
- Valence electrons: 6
The distribution of electrons in these orbitals defines molybdenum’s chemical properties, including its ability to form various oxidation states and bonds with other elements.
