Nature of science:
Experimental evidence to support theories-emission spectra provide evidence for the existence of energy levels. 1.8
Essential idea: The quantized nature of energy transitions is related to the energy states of electrons in atoms and molecules.
In an emission spectrum, the limit of convergence at higher frequency corresponds to the first ionization energy.
Trends in first ionization energy across periods account for the existence of main energy levels and sub-levels in atoms.
Successive ionization energy data for an element give information that shows relations to electron configurations.
Solving problems using E = hv.
Calculation of the value of the first ionization energy from spectral data which gives the wavelength or frequency of the convergence limit.
Deduction of the group of an element from its successive ionization energy data.
Explanation of the trends and discontinuities in first ionization energy across a period.
The value of Planck's constant (h) and E = hf are given in the data booklet in sections 1 and 2.
Use of the Rydberg formula is not expected in calculations of ionization energy.
In 2012 two separate international teams working at the Large Hadron Collider at CERN independently announced that they had discovered a particle with behaviour consistent with the previously predicted "Higgs boson".
"What we observe is not nature itself, but nature exposed to our method of questioning."-Werner Heisenberg.
An electron can behave as a wave or a particle depending on the experimental conditions. Can sense perception giveus objective knowledge about the world?
The de Broglie equation shows that macroscopic particles have too short a wavelength for their wave properties to be observed. Is it meaningful to talk of properties which can never be observed from sense perception?
Electron microscopy has led to many advances in biology, such as the ultrastructure of cells and viruses. The scanning tunnelling microscope (STM) uses a stylus of a single atom to scan a surface and provide a 3-D image at the atomic level.
Topic 3.2-periodic trends
Topic 4.1-ionic bonding
Topic 15.1-lattice enthalpy
Aim 7: Databases could be used for compiling graphs of trends in ionization energies and simulations are available for the Davisson-Germer electron diffraction experiment.