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*Revision Materials and Past Papers* 2.1.1 Atomic structure and isotopes 2.1.2 Compounds, formulae and equations 2.1.3 Amount of substance 2.1.4 Acids 2.1.5 Redox 2.2.1 Electron structure 2.2.2 Bonding and structure 3.1.1 Periodicity 3.1.2 Group 2 3.1.3 The halogens 3.1.4 Qualitative analysis 3.2.1 Enthalpy 3.2.2 Reaction Rates 3.2.3 Chemical equilibrium 4.1 Basic concepts and hydrocarbons 4.1.2 Alkanes 4.1.3 Alkenes 4.2.1 Alcohols 4.2.2 Haloalkanes 4.2.3 Organic synthesis 4.2.4 Analytical techniques 5.1.1 How fast? 5.1.2 How far? 5.1.3 Acids, bases and buffers 5.2.1 Lattice enthalpy 5.2.2 Enthalpy and entropy 5.2.3 Redox and electrode potentials 5.3.1 Transition elements 5.3.2 Qualitative analysis 6.1.1 Aromatic compounds 6.1.2 Carbonyl compounds 6.1.3 Carboxylic acids and esters 6.2.1 Amines 6.2.2 Amino acids, amides and chirality 6.2.3 Polyesters and polyamides 6.2.4 Carbon–carbon bond formation 6.2.5 Organic synthesis 6.3.1 Chromatography and qualitative analysis 6.3.2 Spectroscopy Required Practicals

3.1.1 Periodicity

Periodic trend in electron configuration and ionisation energyPeriodic trend in structure and melting pointThe structure of the periodic table

The Structure of the Periodic Table

Specification Reference 3.1.1 (a)

Quick Notes

  • Elements in the periodic table are arranged by increasing atomic number.
  • Periods = horizontal rows showing repeating trends (periodicity).
  • Groups = vertical columns with similar chemical properties.

Full Notes

Periodic Table Arrangement

The modern periodic table arranges elements by increasing atomic (proton) number.

OCR (A) A-Level Chemistry periodic table diagram showing arrangement of elements by increasing atomic number.

Elements in the same period (row) show repeating trends in physical and chemical properties – this is called periodicity.

Elements in the same group (column) have similar chemical properties as they have the same number of electrons in their outer shell.

OCR (A) A-Level Chemistry periodic table highlighting groups and periods.

Scientific models of the periodic table evolved over time. When he proposed an early version of the modern periodic table, Mendeleev left gaps and predicted undiscovered elements. Over time, the periodic law gradually became accepted and extended with new discoveries that matched his predictions.

Summary