150th Anniversary on 6th March
The IYPT2019 aims to recognize the importance of the Periodic Table of Chemical Elements as one of the most important and influential achievements in modern science reflecting the essence not only of chemistry, but also of physics, biology and other basic sciences disciplines. It also commemorates the v.
Throughout 2019, we will have activities to celebrate the IYPT2019.
Our first event is to join in live with Paris for the launch of IYPT2019 on Tuesday 29th January.
Book on 0429 199 312 to Contact
Dr. Andrey Guryev – CEO PhosAgro
|20:40- 20:50||MUSICAL PERFORMANCE
Mira Yevtich – Brahms Rhapsody Opus 79 number 2
|20:50-21:00||INTRODUCTION TO PROGRAMME
Prof. Natalia Tarasova – IYPT MC co-chair, Past-President of IUPAC
|21:00-21:30||ELEMENTS FOR LIFE
Moderator: Mr. Philip Ball
Ms. Emelia Arthur (FAO/UCN/IIED STEM) – (women) education in Africa
Dr. Marco Mensink (CEO ICCA) – Industry and UN SDG
Prof. Alinka Lépine-Szily (Sao Paolo) – Discovery of new elements
|21:30- 22:55||NOBEL LAUREATE LECTURE
Introduction: Prof. Jan Reedijk, IYPT MC co-chair
PERIODIC TABLE FOR SOCIETY AND THE FUTURE
Prof. Ben Feringa – Nobel Laureate in Chemistry 2016
In 1863 there were 56 known elements with a new element being discovered at a rate of approximately one per year. Other scientists had previously identified periodicity of elements. John Newlands described a Law of Octaves, noting their periodicity according to relative atomic weight in 1864, publishing it in 1865. His proposal identified the potential for new elements such as germanium. The concept was criticized and his innovation was not recognized by the Society of Chemists until 1887. Another person to propose a periodic table was Lothar Meyer, who published a paper in 1864 describing 28 elements classified by their valence, but with no prediction of new elements.
After becoming a teacher in 1867, Mendeleev wrote the definitive textbook of his time: Principles of Chemistry (two volumes, 1868–1870). It was written as he was preparing a textbook for his course. This is when he made his most important discovery. As he attempted to classify the elements according to their chemical properties, he noticed patterns that led him to postulate his periodic table; he claimed to have envisioned the complete arrangement of the elements in a dream:
I saw in a dream a table where all elements fell into place as required. Awakening, I immediately wrote it down on a piece of paper, only in one place did a correction later seem necessary.— Mendeleev, as quoted by Inostrantzev
Unaware of the earlier work on periodic tables going on in the 1860s, he made the following table:
|Cl 35.5||K 39||Ca 40|
|Br 80||Rb 85||Sr 88|
|I 127||Cs 133||Ba 137|
By adding additional elements following this pattern, Mendeleev developed his extended version of the periodic table. On 6 March 1869, he made a formal presentation to the Russian Chemical Society, titled The Dependence between the Properties of the Atomic Weights of the Elements, which described elements according to both atomic weight and valence. This presentation stated that
- The elements, if arranged according to their atomic weight, exhibit an apparent periodicity of properties.
- Elements which are similar regarding their chemical properties either have similar atomic weights (e.g., Pt, Ir, Os) or have their atomic weights increasing regularly (e.g., K, Rb, Cs).
- The arrangement of the elements in groups of elements in the order of their atomic weights corresponds to their so-called valencies, as well as, to some extent, to their distinctive chemical properties; as is apparent among other series in that of Li, Be, B, C, N, O, and F.
- The elements which are the most widely diffused have small atomic masses.
- The magnitude of the atomic weight determines the character of the element, just as the magnitude of the molecule determines the character of a compound body.
- We must expect the discovery of many yet unknown elements – for example, two elements, analogous to aluminum and silicon, whose atomic weights would be between 65 and 75.
- The atomic weight of an element may sometimes be amended by a knowledge of those of its contiguous elements. Thus the atomic weight of tellurium must lie between 123 and 126, and cannot be 128. (Tellurium’s atomic mass is 127.6, and Mendeleev was incorrect in his assumption that atomic mass must increase with position within a period.)
- Certain characteristic properties of elements can be foretold from their atomic weights.
Mendeleev published his periodic table of all known elements and predicted several new elements to complete the table in a Russian-language journal. Only a few months after, Meyer published a virtually identical table in a German-language journal. Mendeleev has the distinction of accurately predicting the qualities of what he called ekasilicon, ekaaluminium and ekaboron (germanium, gallium and scandium, respectively).
For his predicted eight elements, he used the prefixes of eka, dvi, and tri (Sanskrit one, two, three) in their naming. Mendeleev questioned some of the currently accepted atomic weights (they could be measured only with a relatively low accuracy at that time), pointing out that they did not correspond to those suggested by his Periodic Law. He noted that tellurium has a higher atomic weight than iodine, but he placed them in the right order, incorrectly predicting that the accepted atomic weights at the time were at fault. He was puzzled about where to put the known lanthanides, and predicted the existence of another row to the table which were the actinides which were some of the heaviest in atomic mass. Some people dismissed Mendeleev for predicting that there would be more elements, but he was proven to be correct when Ga (gallium) and Ge (germanium) were found in 1875 and 1886 respectively, fitting perfectly into the two missing spaces.