What is the element that has the ending configuration of 4d^4

Molybdenum

Explanation:

Molybdenum is a chemical element with the symbol Mo and an atomic number of 42. This implies a total of 42 electrons in its orbital.

The atomic weight of  Mo is 95.94g/mol.

Using the sublevel notation system, the electrons can be filled into the orbitals as shown below:

                      1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d⁴

        The ending configuration of this element is therefore 4d⁴

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