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Atomic Structure Practice (Interactive)

Intuition

Atomic structure practice is like mapping uncharted territory, each problem reveals new patterns in electron configuration: Mastering atomic structure requires understanding how electrons fill orbitals and how this determines chemical properties

Why it matters: Atomic structure knowledge is essential for predicting chemical behavior and understanding the periodic table

The key insight: Mastering atomic structure requires understanding how electrons fill orbitals and how this determines chemical properties

IB Chemistry, Atomic Structure Practice

8 auto-graded practice problems at medium to hard difficulty, aligned to the IB Chemistry syllabus (SL/HL). Select an answer, submit, and review the explanation.

Electron Configuration

Common Mistakes

Confusing mass number with atomic mass: Mass number is the count of protons + neutrons (integer). Atomic mass is the actual mass in unified atomic mass units (not necessarily an integer). Don’t round atomic mass to get mass number.

Assuming electrons have significant mass: Electrons have approximately 1/1836 the mass of a proton. For most calculations, electron mass is negligible. Don’t include it in mass number calculations.

Forgetting that isotopes have the same chemical properties: Isotopes differ only in neutron number. They have identical electron configurations and therefore identical chemical behaviour. Don’t assume different isotopes behave differently chemically.

Cross-References