Step 1: Identify the atomic number of Chromium (Cr), which is 24.
Step 2: Write the electron configuration by filling the orbitals in order of increasing energy levels.
Step 3: Fill the 1s, 2s, 2p, 3s, and 3p orbitals first, which accounts for 18 electrons (1s2 2s2 2p6 3s2 3p6).
Step 4: Next, fill the 4s orbital with 2 electrons (4s2), bringing the total to 20 electrons.
Step 5: Now, fill the 3d orbital. Normally, you would fill it with 10 electrons (3d10), but Chromium is special.
Step 6: Instead of filling the 3d orbital completely, Chromium has 5 electrons in the 3d orbital (3d5) and only 1 electron in the 4s orbital (4s1) for stability.
Step 7: Combine the filled orbitals to write the final electron configuration: [Ar] 3d5 4s1.
