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Variable Oxidation States When transition elements forms ions they lose electrons from the 4s subshell first This is because when the orbitals are occupied, the repulsion between electrons pushes t...
Transition Elements Transition metals are elements with an incomplete d-subshell or that can form at least one stable cation with an incomplete d-subshell This definition distinguishes them from d-...
Trends Across a Period Ionisation energies show periodicity – a trend across a period of the Periodic Table As could be expected from their electron configuration, the group 1 metals have a relativ...
Convergence Limits on an Emission Spectrum Emission Spectra Electrons move rapidly around the nucleus in energy shells Heat or electricity can be used to excite an electron to a higher main energy ...
Analysing Graphs The gradient of a graph can be found by: In the case of a straight line graph: using a triangle and the equation for a straight line In the case of a curve: drawing a tangent to th...
Drawing Graphs General guidance on drawing graphs Graphs need to have: Clear title Labelled axes Units on the axes Appropriate linear scales without any jumps This means the plotted graph must occu...
Percentage Error Percentage error is used to express the difference between a final calculated answer and an accepted or literature value It is calculated using the following formula You should be ...
Reducing Errors Random errors can be reduced by repeated trials and measurements Multiple measurements when averaged will reduce the impact of a random error on the average The more readings you ha...
Types of Errors An error is the difference between a value or quantity obtained in an experiment and an accepted or literature value for an experiment There are two types of errors in experiments, ...
