Unit 1: Topic 1 Atomic Structure Flashcards
Q: How are atoms modeled?
A: Atoms are modeled as a nucleus surrounded by electrons in distinct energy levels.
Q: What is atomic number (Z)?
A: The number of protons in an atom’s nucleus.
Q: What is mass number (A)?
A: The total number of protons and neutrons in an atom’s nucleus.
Q: What are isotopes?
A: Atoms of the same element with different numbers of neutrons.
Q: How do you use nuclear notation AZX to determine subatomic particles?
A: - Protons = Z
Neutrons = A - Z
Electrons = Z (in neutral atoms), adjusted for charge in ions.
Q: Rank the s, p, and d orbitals by relative energy.
A: s < p < d in increasing energy.
Q: What principles govern electron configurations?
Aufbau principle
Hund’s rule
Pauli exclusion principle
Aufbau principle:
Fill lower energy orbitals first.
Hund’s rule
Electrons occupy orbitals singly before pairing.
Pauli exclusion principle
No two electrons in an atom can have the same four quantum numbers.
Q: Write the electron configuration for chlorine (Z = 17).
A: Full: 1s² 2s² 2p⁶ 3s² 3p⁵
Condensed: [Ne] 3s² 3p⁵
Q: What are the exceptions in electron configuration?
Cr (Chromium): [Ar] 4s¹ 3d⁵ instead of [Ar] 4s² 3d⁴
Cu (Copper): [Ar] 4s¹ 3d¹⁰ instead of [Ar] 4s² 3d⁹
Q: How is ionisation energy data linked to electron configuration?
A: Successive ionisation energies show large jumps when removing core electrons, indicating shell structure.
