The Main Building Blocks Of Chemical Substance

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Question 1 1669 – Hennig Brand discovered Phosphorus through his attempt to create a Philosopher’s Stone 1743 – 1794 – Antoine Lavoisier established that elements are the fundamental building blocks of chemical substance. He defined an element as ‘a substance that could not be composed into simpler substances. He identified four groups; metals, non-metal, elastic fluids (gas) and earth after examining the physical and chemical properties. 1829 – Johann Dobereiner developed the Law of Triads; the middle element’s atomic weight was the average of the other two elements. The elements within each triad were organised by atomic weight and noted that many characteristics of the middle elemetns would mediate between the three. 1863 – John Newlands discovered the Law of Octaves; elements exhibited similar behaviours and possessed similar physical and chemical properties to the eighth element following it in the table. 1864 – Lothar Meyer developed a periodic table with only 28 elements organised by valence. His version of the periodic table was often disregarded in comparison to Mendeleev’s which was published around the same time as he did not leave gaps for undiscovered elements whereas Mendeleev did. 1869 – Dmitri Mendeleev produced a periodic table based on the atomic weight but arrange ‘periodically’ with elements with similar properties under each other. His table consisted of the 66 known elements, but he left gaps for those which were undiscovered. He believed that it
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