Begin with 3 free Unit 04 practice problems. When you want more reps on configurations, sublevels, orbital rules, and valence patterns, premium unlocks Quick Sets of 3, Standard Sets of 9, and Extended Sets of 18 from this 81-problem bank.
3 Free Sample Problems
Work these 3 to find out whether the electron configuration filling patterns are clicking — or whether they need more deliberate, careful repetitions before they will.
#4Valence Electrons
How many valence electrons does a nitrogen atom (N, Z = 7) have? Write the full configuration to verify.
#5Hund's Rule
Hund's Rule states that when filling orbitals of equal energy, electrons…
#6Quantum Numbers
Which set of quantum numbers (n, l, ml, ms) is NOT valid for any electron?
Prep for the test — not just the homework
The 3 free problems show you where you stand. The full bank is how you close the gaps before the test.
Randomized every time — fresh problems that force real understanding, not answer memorization
Full worked solutions — see exactly where your setup went off track, not just whether you were right
81 problems across electron configurations, orbital diagrams, and sublevel rules
Quick (3), Standard (9), or Extended (18) — use whatever fits your schedule
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General Chemistry · Unit 04 · Electron Configuration Practice