You'll find it hanging on the wall of the chemistry lab in every school in the world, or against the backdrop of computers obsessed with chemistry.
For decades, generations of children who sang songs for its elements - more than 100 - had successively made to keep them easy.
Of course what we are talking about here is the periodic table of the elements, and what is unique about this year is that it has reached its 150th year.
With its candle lit 150, it's time to test your knowledge about the periodic table.
The United Nations named 2019 the International Year of the Periodic Table, and thus celebrates one of the most important scientific achievements. This event will complete its session in March of this year, the month in which the Russian chemist Dmitri Mendeleev announced his periodic schedule, and he arranged within the known chemical elements at that time.
A century and a half ago, Mendeleyev's ideas withstood the test of time, although he presented them long before knowledge of the finer things of matter and the nature of the structure of atoms and subatomic particles.
Strange concept?
Dr. Peter Wothers of Cambridge University, who is an expert in this field, believes that if aliens come to Earth, this scientific banner must draw their attention. “Is there a periodic table for aliens?” He asks. I think they often have such a schedule, which is more fundamental than just human creativity. There is something innate about it, there is a chemical and physical law behind it. ”
Chemistry laws
Mendeleev (1834-1907) devised his early periodic table in 1869. At that point, Mendeleev took the 63 known elements at the time and arranged them together in a table mainly dependent on their atomic masses.
Although Mendeleev was not the first to do so, his interpretation included a creative leap. Mendeleev put on his table the elements of similar characteristics under each other in groups. And he left gaps between them to include new items that are expected to be discovered later.
“People have been doing this for a long time, but in the end there was a little bit of a natural basis,” Dr. Weatherers says. Or to say a law that meant it had to be arranged in some way. ”
The 150 years that separate us from those days have witnessed many fundamental changes in our understanding of matter. "It seems clear that Mendeleev did not know about the subatomic structure at the time," says Weatherers. So he based his work on atomic weights only, which were not necessarily known at the time.
After discovering protons, scientists realized that the atomic number of an element (the number of protons in its nucleus) is more important for the arrangement of elements. So the elements in the modern periodic table are arranged according to their atomic number, and not according to their relative atomic masses. We now know how to do this, and that relates to quantum mechanics, the arrangement of electrons in atoms, and so on.
Now, the number of elements exceeds 100, arranged according to the increasing atomic number. There are repeated patterns of object properties, and it is precisely this that gives the periodic table its name. Where elements with similar properties are arranged to form columns (groups). Today's periodic table is aesthetic and practical in nature. You can see some properties of the element by looking at its position in the periodic table only, or by looking at its arrangement, and this makes the table extremely important for chemists.
Symmetry fun
This year, which has been called the year of the periodic table, may also represent the heyday of his youth. Currently, the seventh cycle of the periodic table is complete plus the last of four elements in December 2015. This addition made it complete and even beautiful.
So, today we are fortunate that the periodic scheduling is complete, and perhaps this perfection is the most brilliant of the periodic table ever.
Many scientists today are working on installing heavier elements (which are not present in their natural form), and if that goes on the right track, the face of the periodic table will change again.
If we happen and get only one new element, we will have to add an eighth grade, it is the eighth session! The periodic table will lose some of its beauty at that time, as the prevailing belief among scientists today is that it is impossible to complete the eighth session of the table to remain as a memorial to the limited scientific capabilities.
