History of the Modern Periodic Table of Elements PDF

CITI GLOBAL COLLEGE - CABUYAO CAMPUS HISTORY OF THE MODERN PERIODIC TABLE OF ELEMENTS PHYSICAL SCIENCE A.Y 2024-2025 AT THE END OF THE LESSON, LEARNERS ARE EXPECTED TO: DEFINE THE BASIC CONCEPTS IN PERIODIC TABLE OF ELEMENTS RECOGNIZE THE BASIC CONCEPTS IN PERIODIC TABLE OF ELEMENTS AND T...

CITI GLOBAL COLLEGE - CABUYAO CAMPUS HISTORY OF THE MODERN PERIODIC TABLE OF ELEMENTS PHYSICAL SCIENCE A.Y 2024-2025 AT THE END OF THE LESSON, LEARNERS ARE EXPECTED TO: DEFINE THE BASIC CONCEPTS IN PERIODIC TABLE OF ELEMENTS RECOGNIZE THE BASIC CONCEPTS IN PERIODIC TABLE OF ELEMENTS AND THE SCIENTISTS THAT ORGANIZED IT INTERPRET THE BASIC PARTS OF THE PERIODIC TABLE OF ELEMENTS INTRODUCTION WHAT IS PERIODIC TABLE? Periodic table, in chemistry, the organized array of all the chemical elements in order of increasing atomic number—i.e., the total number of protons in the atomic nucleus. When the chemical elements are thus arranged, there is a recurring pattern called the “periodic law” in their properties, in which elements in the same column (group) have similar properties. The initial discovery, which was made by Dmitry I. Mendeleev in the mid-19th century, has been of inestimable value in the development of chemistry. CHRONOLOGICAL TIMELINE OF PERIODIC TABLE During the 19th century, chemists began to categorize the elements according to similarities in their physical and chemical properties. The end result of these studies was our modern periodic table. JOHANN DOBEREINER 1780 – 1849 MODEL OF TRIADS In 1829, he classified some elements into groups of three, which he called triads. The elements in a triad had similar chemical properties and orderly physical properties. Example: Chloride, Bromine, Iodine, Calcium, Strontium, and Barium JOHN NEWLANDS 1838 – 1898 LAW OF OCTAVES In 1863, he suggested that elements be arranged in “octaves” because he noticed (after arranging the elements in order of increasing atomic mass) that certain properties repeated every 8th element. The major problem in Newland’s laws of octaves was the elements with greater atomic masses could not be accommodated into octaves. The elements that were discovered later could not be fit into the octave pattern. Therefore, this method of classifying elements did not leave any room for the discovery of new elements. DMITRI MENDELEEV 1834 – 1907 FATHER OF PERIODIC TABLE In 1869, Russian chemist and teacher Dmitri Mendeleev (1836-1907) published a periodic table of the elements by its organized increasing atomic mass. Mendeleev was writing a chemistry textbook for his students and wanted to organize all of the known elements at that time according to their chemical properties. He famously organized the information for each element onto separate note cards that were then easy to rearrange as needed. He discovered that when he placed them in order of increasing atomic mass, certain similarities in chemical behavior repeated at regular intervals. This type of a repeating pattern is called "periodic". A pendulum that swings back and forth in a given time interval is periodic, as is the movement of the moon around the Earth. MENDELEEV CONSIDERED AS THE FATHER OF THE PERIODIC TABLE BECAUSE: He stated that if the atomic weight of an element caused it to be placed in the wrong group, then the weight must be wrong. Mendeleev corrected the atomic masses of Beryllium, Indium, and Uranium. Mendeleev was so confident in his table that he used it to predict the physical properties of three elements that were yet unknown, After the discovery of these unknown elements between 1874 and 1885, and the fact that Mendeleev’s predictions for Scandium, Gallium, and Germanium were amazingly close to the actual values, his table was generally accepted Chemical Society. HENRY MOSELEY 1887 – 1915 In 1913, through his work with X- rays, he determined the actual nuclear charge (atomic number) of the elements. He rearranged the elements in order of increasing atomic number. GLENN T. SEABORG 1912 – 1999 After co-discovering 10 new elements, in 1994 he moved 14 elements out of the main body of the periodic table to their current location below Lanthanide series. These became known as the Actinide series. IUPAC 1919 – PRESENT Its goal is to unite a fragmented, global chemistry community for the advancement of the chemical sciences via collaboration and the free exchange of scientific information. The International Union of Pure and Applied Chemistry (IUPAC), established in 1919, was formed by chemists from both industry and academia. The International Union of Pure and Applied Chemistry (IUPAC) is the world authority on chemical nomenclature, terminology (including the naming of new elements in the periodic table), standardized methods for measurement, atomic weights and many other critically-evaluated data. It develops and maintains Recommendations that create a common language for the global chemistry community. PERIODIC TABLE GEOGRAPHY PERIODIC TABLE GEOGRAPHY PERIODIC TABLE GEOGRAPHY PERIODIC LAW: WHEN ELEMENTS ARE ARRANGED IN ORDER OF INCREASING ATOMIC NUMBER, THERE IS A PERIODIC PATTERN IN THEIR PHYSICAL AND CHEMICAL PROPERTIES. PERIODIC TABLE GEOGRAPHY PERIODIC TABLE GEOGRAPHY PERIODIC TABLE GEOGRAPHY PERIODIC TABLE GEOGRAPHY PERIODIC TABLE GEOGRAPHY THANK YOU!