Emission spectra are produced by atoms emitting photons when electrons in excited states return to lower energy levels.
Qualitatively describe the relationship between colour, wavelength, frequency and energy across the electromagnetic spectrum.
Distinguish between a continuous and a line spectrum.
Details of the electromagnetic spectrum are given in the data booklet.
The line emission spectrum of hydrogen provides evidence for the existence of electrons in discrete energy levels, which converge at higher energies.
Describe the emission spectrum of the hydrogen atom, including the relationships between the lines and energy transitions to the first, second and third energy levels.
The names of the different series in the hydrogen emission spectrum will not be assessed.
The main energy level is given an integer number, n, and can hold a maximum of 2 n2 electrons.
Deduce the maximum number of electrons that can occupy each energy level.
A more detailed model of the atom describes the division of the main energy level into s, p, d and f sublevels of successively higher energies.
Recognize the shape and orientation of an s atomic orbital and the three p atomic orbitals.
Each orbital has a defined energy state for a given electron configuration and chemical environment, and can hold two electrons of opposite spin.
Sublevels contain a fixed number of orbitals, regions of space where there is a high probability of finding an electron.
Apply the Aufbau principle, Hund’s rule and the Pauli exclusion principle to deduce electron configurations for atoms and ions up to .
Full electron configurations and condensed electron configurations using the noble gas core should be covered.
Orbital diagrams, i.e. arrow-in-box diagrams, should be used to represent the filling and relative energy of orbitals.
The electron configurations of Cr and Cu as exceptions should be covered.
In an emission spectrum, the limit of convergence at higher frequency corresponds to ionization.
Explain the trends and discontinuities in first ionization energy (IE) across a period and down a group.
Calculate the value of the first IE from spectral data that gives the wavelength or frequency of the convergence limit.
The value of the Planck constant () and the equations and are given in the data booklet.
Successive ionization energy (IE) data for an element give information about its electron configuration.
Deduce the group of an element from its successive ionization data. Databases are useful for compiling graphs of trends in IEs.