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20th of April

The 20th of April is the 110th day of the year (Gregorian calendar) or 111th in a leap year. 


Annual Commemoration and Observant Days



The 20th of April is known as ‘UN Chinese Language Day’ established by the UNESCO (United Nations Education, Science and Cultural Organisation) similarly to all UN language days to celebrate the language and cultural diversity of the world



The 20th of April is known as ‘National Donor Day’ in Russia, commemorating the first successful blood transfusion in the country which took place on this day in 1832. In Russia blood donors are more revered than they are in the rest of the world and this is a day used to celebrate their contributions to the nation.








Historical Events


20th of April


On the 20th of April 1946

The League of Nations was dissolved on this day. The League of Nations was formed at the end of World War I with the primary purpose of preventing another conflict of similar magnitude. After the End of World War II it was evident that the League of Nations had failed but however it was the precursor to the United Nations which formed soon after.


On the 20th of April 1902

Radium was first isolated as the salt Radium Chloride by Marie and Pierre Curie.


In 1903 they both received the Nobel Prize for their research into radiation and Marie became the first women to receive the prize. Marie started studying Uranium for her PhD (doctorial) thesis in Poland. Pierre was a famous physicist and chemist who later joined Marie on her research. While Marie worked to isolate the various components Pierre worked on the physical characteristics of the isolated components. Through their research into pitchblende (a natural ore made mainly of Radium oxides UO2 and UO3) they managed to discover and isolate Radium and Plutonium which is produced as the Uranium decays into more radioactive elements (see the ‘decay chain’ of Uranium for more information). They named Radium from the Latin word ‘Radius’ meaning ray when they first identified it as a new element in 1898. As Radium is not found freely in nature and so it took Marie a long time to isolate less than a gram of radium chloride from several tons of pitchblende. Due to the minute amount of Polonium found in pitchblende. After discovering polonium they named the substance after Marie’s home country of Poland. After Pierre’s death from an accident on the 19th of April 1906 Marie was forced to continue her work without her husband. In 1910 she managed to finally isolate pure Radium which gained her another Nobel Prize the following year making her the first person to win two Nobel Prizes.