#MoleDay / Wereld Mol Dag 2023
2023-10-23 06:02 - 18:02 (Europe/Amsterdam)
Mole Day is an unofficial holiday celebrated among chemists, chemistry students and chemistry enthusiasts on October 23, between 06:02 and 18:02 (6:02 pm), making the date 6:02 10/23 in the American style of writing dates.
The time and date are derived from the Avogadro number, which is approximately 6.02×1023, defining the number of particles (atoms or molecules) in one mole (mol) of substance, one of the seven base SI units. Schools around the world celebrate Mole Day with various activities related to chemistry and/or moles. For a given molecule, one mole is a mass (in grams) whose number is equal to the molar mass of the molecule. For example, the water molecule has an molar mass of 18, therefore one mole of water weighs 18 grams. Similarly, a mole of neon has a molar mass of 20 grams. In general, one mole of any substance contains Avogadro’s Number of molecules or atoms of that substance. This relationship was first discovered by Amedeo Avogadro (1776-1858) and he received credit for this after his death. 2023 Theme: Sherlock Molmes!
Links:
Mole Day
Mol (eenheid)

Periodic Table Day / Dag van het Periodiek systeem 2024
2024-02-07
The periodic table (Periodiek systeem), also known as the periodic table of elements, is a tabular display of the chemical elements, which are arranged by atomic number, electron configuration, and recurring chemical properties.
The structure of the table shows periodic trends. The seven rows of the table, called periods, generally have metals on the left and nonmetals on the right. The columns, called groups, contain elements with similar chemical behaviours. Six groups have accepted names as well as assigned numbers: for example, group 17 elements are the halogens; and group 18 are the noble gases. Also displayed are four simple rectangular areas or blocks associated with the filling of different atomic orbitals. The elements from atomic numbers 1 (hydrogen) to 118 (oganesson) have all been discovered or synthesized, completing seven full rows of the periodic table. The first 94 elements, hydrogen to plutonium, all occur naturally, though some are found only in trace amounts and a few were discovered in nature only after having first been synthesized. Elements 95 to 118 have only been synthesized in laboratories, nuclear reactors, or nuclear explosions. The synthesis of elements having higher atomic numbers is currently being pursued: these elements would begin an eighth row, and theoretical work has been done to suggest possible candidates for this extension. Numerous synthetic radioisotopes of naturally occurring elements have also been produced in laboratories.
The organization of the periodic table can be used to derive relationships between the various element properties, and also to predict chemical properties and behaviours of undiscovered or newly synthesized elements. Russian chemist Dmitri Mendeleev published the first recognizable periodic table in 1869, developed mainly to illustrate periodic trends of the then-known elements. He also predicted some properties of unidentified elements that were expected to fill gaps within the table. Most of his forecasts soon proved to be correct, culminating with the discovery of gallium and germanium in 1875 and 1886 respectively, which corroborated his predictions. Mendeleev’s idea has been slowly expanded and refined with the discovery or synthesis of further new elements and the development of new theoretical models to explain chemical behaviour. The modern periodic table now provides a useful framework for analyzing chemical reactions, and continues to be widely used in chemistry, nuclear physics and other sciences. Some discussion remains ongoing regarding the placement and categorisation of specific elements, the future extension and limits of the table, and whether there is an optimal form of the table.
Links:
Periodic Table Day
Alternative periodic tables
Mendeleev first presented his periodic table on 06-03-1869 to the Russian Chemical Society
APOD: 2020 August 9 – The Origin of Elements
ChemHaiku
Kwantummechanica

The Nobel Prize in Chemistry 2024
2024-10-09 11:45 - 12:15
The Nobel Prize in Chemistry 2024 is about proteins, life’s ingenious chemical tools.
David Baker has succeeded with the almost impossible feat of building entirely new kinds of proteins. Demis Hassabis and John Jumper have developed an AI model to solve a 50-year-old problem: predicting proteins’ complex structures. These discoveries hold enormous potential.
Links:
The Nobel Prize
Press release
Popular information: They have revealed proteins’ secrets through computing and artificial intelligence
Scientific background: Computational protein design and protein structure prediction

#MoleDay / Wereld Mol Dag 2024
2024-10-23 06:02 - 18:02
Mole Day is an unofficial holiday celebrated among chemists, chemistry students and chemistry enthusiasts on October 23, between 06:02 and 18:02 (6:02 pm), making the date 6:02 10/23 in the American style of writing dates.
The time and date are derived from the Avogadro number, which is approximately 6.02×1023, defining the number of particles (atoms or molecules) in one mole (mol) of substance, one of the seven base SI units. Schools around the world celebrate Mole Day with various activities related to chemistry and/or moles. For a given molecule, one mole is a mass (in grams) whose number is equal to the molar mass of the molecule. For example, the water molecule has an molar mass of 18, therefore one mole of water weighs 18 grams. Similarly, a mole of neon has a molar mass of 20 grams. In general, one mole of any substance contains Avogadro’s Number of molecules or atoms of that substance. This relationship was first discovered by Amedeo Avogadro (1776-1858) and he received credit for this after his death.
Links:
Mole Day
Mol (eenheid)

Periodic Table Day / Dag van het Periodiek systeem 2025
2025-02-07
The periodic table (Periodiek systeem), also known as the periodic table of elements, is a tabular display of the chemical elements, which are arranged by atomic number, electron configuration, and recurring chemical properties.
The structure of the table shows periodic trends. The seven rows of the table, called periods, generally have metals on the left and nonmetals on the right. The columns, called groups, contain elements with similar chemical behaviours. Six groups have accepted names as well as assigned numbers: for example, group 17 elements are the halogens; and group 18 are the noble gases. Also displayed are four simple rectangular areas or blocks associated with the filling of different atomic orbitals. The elements from atomic numbers 1 (hydrogen) to 118 (oganesson) have all been discovered or synthesized, completing seven full rows of the periodic table. The first 94 elements, hydrogen to plutonium, all occur naturally, though some are found only in trace amounts and a few were discovered in nature only after having first been synthesized. Elements 95 to 118 have only been synthesized in laboratories, nuclear reactors, or nuclear explosions. The synthesis of elements having higher atomic numbers is currently being pursued: these elements would begin an eighth row, and theoretical work has been done to suggest possible candidates for this extension. Numerous synthetic radioisotopes of naturally occurring elements have also been produced in laboratories.
The organization of the periodic table can be used to derive relationships between the various element properties, and also to predict chemical properties and behaviours of undiscovered or newly synthesized elements. Russian chemist Dmitri Mendeleev published the first recognizable periodic table in 1869, developed mainly to illustrate periodic trends of the then-known elements. He also predicted some properties of unidentified elements that were expected to fill gaps within the table. Most of his forecasts soon proved to be correct, culminating with the discovery of gallium and germanium in 1875 and 1886 respectively, which corroborated his predictions. Mendeleev’s idea has been slowly expanded and refined with the discovery or synthesis of further new elements and the development of new theoretical models to explain chemical behaviour. The modern periodic table now provides a useful framework for analyzing chemical reactions, and continues to be widely used in chemistry, nuclear physics and other sciences. Some discussion remains ongoing regarding the placement and categorisation of specific elements, the future extension and limits of the table, and whether there is an optimal form of the table.
Deze periodieke tabel toont de primaire bron voor elk element, klik op afbeelding om bericht te lezen
Links:
Periodic Table Day
Alternative periodic tables
Mendeleev first presented his periodic table on 06-03-1869 to the Russian Chemical Society
APOD: 2020 August 9 – The Origin of Elements
ChemHaiku
Periodic Videos
Kwantummechanica

The Nobel Prize in Chemistry 2025
2025-10-08 11:45 - 12:15
The Nobel Prize in Chemistry 2025 was awarded to Susumu Kitagawa, Richard Robson and Omar M. Yaghi “for the development of metal-organic frameworks.”
The Nobel Prize laureates in chemistry 2025 have created molecular constructions with large spaces through which gases and other chemicals can flow. These constructions, metal-organic frameworks, can be used to harvest water from desert air, capture carbon dioxide, store toxic gases or catalyse chemical reactions.
Links:
The Nobel Prize

#MoleDay / Wereld Mol Dag 2025
2025-10-23 06:02 - 18:02

DNA Day 2026
2026-04-25
DNA Day is a United States holiday celebrated on April 25, it commemorates the day in 1953 when James Watson, Francis Crick, Maurice Wilkins, Rosalind Franklin and colleagues published papers in the journal Nature on the structure of DNA.
Furthermore, in early April 2003 it was declared that the Human Genome Project was very close to complete, and “the remaining tiny gaps were considered too costly to fill.” In the United States, DNA Day was first celebrated on April 25, 2003, by proclamation of both the Senate and the House of Representatives. However, they only declared a one-time celebration, not an annual holiday. Every year from 2003 onward, annual DNA Day celebrations have been organized by the National Human Genome Research Institute (NHGRI), starting as early as April 23 in 2010, April 15 in 2011 and April 20 in 2012. April 25 has since been declared “International DNA Day” and “World DNA Day” by several groups. Genealogical DNA testing companies and genetic genealogy publishers run annual sales around DNA Day, seeking interest from the public and promoting their services.
Links:
DNA Day
ESHG DNA Day Essay & Video Contest
