Determine the total number of electrons, the number of valence electrons, and the name of the element with each electronic configuration.[Ar] 4s2, 3d5
The electronic configuration [Ar] 4s2, 3d5 refers to the element Chromium (Cr).
- Total number of electrons: The electronic configuration tells us the arrangement of electrons in an atom. The total number of electrons can be determined by adding up the number of electrons in each orbital. In this case, we have:
[Ar] (Argon configuration) = 18 electrons
4s2 = 2 electrons
3d5 = 5 electrons
Total number of electrons = 18 + 2 + 5 = 25 electrons
- Number of valence electrons: The valence electrons are the electrons in the outermost energy level (shell) of an atom. In this case, the outermost energy level is the 4th energy level, which includes the 4s and 3d orbitals. The number of valence electrons corresponds to the electrons in the 4s and 3d orbitals. Therefore, the number of valence electrons is 2.
- Name of the element: The electronic configuration [Ar] 4s2, 3d5 corresponds to the element Chromium (Cr) which has an atomic number of 24.