Lesson Slideshow Section 01
Unit Summary Section 02
Key Concepts
Mass Spectrometry, Subshells (s, p, d, f), Aufbau Principle, Hund's Rule, Pauli Exclusion Principle
Assessment Objectives
Write configurations, Explain orbital filling, Interpret mass spectra data
Prior Knowledge Needed
Bohr model, protons/neutrons/electrons, isotopes (Theme 3)
IB Syllabus Reference
S1.3
Interactive Study Guide
Click here to view the full, detailed topic summary for this unit.
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Cu
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Video Lesson Section 03
Video Instruction
1 Lessons Available
Electron Configuration
Practice Quiz Section 04 · Interactive
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Ne
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Vocabulary Review Section 05
Orbital
A region of space where there is a high probability (90%+) of finding an electron.
Subshell
A subdivision of an energy level (s, p, d, f) containing group of orbitals with the same energy.
Principal Energy Level
The shell occupied by electrons, denoted by the quantum number n.
Quantized
Restricted to specific, discrete values of energy rather than a continuous range.
Emission Spectrum
A series of discrete lines produced when electrons drop from higher to lower energy levels.
Aufbau Principle
Electrons fill the lowest available energy levels before moving to higher ones.
Pauli Exclusion Principle
An orbital can hold a maximum of two electrons, and they must have opposite spins.
Hund's Rule
Electrons fill degenerate orbitals singly first, with parallel spins, to minimize repulsion.
Degenerate Orbitals
Orbitals that have the same energy level ($e.g. \text{the three p-orbitals in a subshell}$).
Isotopes
Atoms of the same element with the same number of protons but different numbers of neutrons.
Relative Atomic Mass ($A_r$)
The weighted average mass of an atom compared to 1/12th of carbon-12.
Mass Spectrometry
Analytical technique used to determine the relative abundance of isotopes in a sample.
Valence Electrons
Electrons in the outermost energy level of an atom, responsible for bonding.
Shielding
The reduction in nuclear attraction on outer electrons by inner shell electrons.
Photon
A discrete packet (quantum) of electromagnetic radiation.
Ground State
The lowest energy state of an atom where electrons fill the orbital closest to the nucleus.
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Fe
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Revision Notes Section 06
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Au
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Practice Tests Section 07
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Cl
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Worksheets & Labs Section 08