History of the Periodic Table - 2.2b, 2.2c, 2.2i

The Periodic Table and Periodicity - OCR GCSE (J248)

In this course, Dr Nick Chatterton (Birkbeck College, University of London), we explore the history and organisation of the periodic table, focusing on elements' properties, atomic numbers, and electron configurations for the OCR GCSE (9-1) in Chemistry A (J248) for Higher/Foundation Tier. We (i) discuss how elements in the same group have similar chemical properties due to their equal number of outer electrons (Topics 2.2b, 2.2c, 2.2i). Next, (ii) we then learn about electron configurations (Topics 2.2b, 2.2c); before (iii) giving specific attention to Group 1 (alkali metals) and Group 7 (halogens) elements, understanding their reactivity trends and characteristic reactions (Topics 4.1a, 4.1b); before finally (iv) examining Group 0 (noble gases) elements and their unreactive nature due to complete outer electron shells (Topics 4.1a-f).

History of the Periodic Table - 2.2b, 2.2c, 2.2i

In this lecture, we introduce the history of the periodic table (Topics 2.2b, 2.2c, 2.2i). Initially, elements were listed based on their properties, with early breakthroughs made by Lavoisier and Newlands in recognizing the periodicity of elements. The significant breakthrough, however, came from Russian scientist Mendeleev, who organised the elements based on both atomic weight and chemical properties, leading to the modern periodic table. Today's periodic table is organised by the number of subatomic particles, particularly the atomic number (number of protons), and still follows Mendeleev's concept of grouping elements with similar chemical properties.