Write the orbital notation for chromium. Type your answer using the noble gas abbreviation of the configuration and only the symbols in the table below. Enter the major energy levels with their sublevels in the order in which they are filled. Enter filled orbitals in a sublevel first, followed by half-filled orbitals, and then empty orbitals. Enter two underscore symbols for an empty orbital. For example, the answer for carbon is [He] ^v ^_ ^_ __.
http://www.mrl.ucsb.edu/~seshadri/2004_100A/100A_Orbitals.pdf
To determine the orbital notation for chromium, we need to identify the electron configuration by following the Aufbau principle, Pauli exclusion principle, and Hund's rule.
The noble gas abbreviation for chromium is [Ar] because it is the nearest noble gas before chromium in the periodic table.
Now, let's determine the electron configuration of chromium:
1. The noble gas abbreviation [Ar] represents the first 18 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰.
2. Chromium is in the 4th period, and we need to add the remaining electrons.
3. The 4th period starts with the 4s orbital, so we write the 4s².
4. The 3d orbitals should be filled next, but we encounter an exception with chromium. Instead of filling the 3d orbitals after 4s, one electron moves from the 4s orbital to the 3d orbital. So, the electron configuration for chromium is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵.
Now, let's represent this electron configuration using orbital notation:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵
Using the orbital notations (^v for filled, ^_ for half-filled, and __ for empty), we can write the orbital notation for chromium using the noble gas abbreviation:
[Ar] 4s¹ 3d⁵
Therefore, the orbital notation for chromium using the noble gas abbreviation is [Ar] 4s¹ 3d⁵.