Xinhua News Agency, Beijing, March 7th New Media Specialist British media said that some people doubt whether the current periodic table is the best arrangement.
According to the February 26th report of the British New Scientist Weekly website, at present, the chemical elements are arranged according to the number of protons in the nucleus. Moreover, the nature of the elements is primarily determined by the arrangement of extranuclear electrons.
The lightest element has only one electronic layer, and the heavier element has more electronic layers. What really determines the nature of each element is the outermost electron count.
The arrangement of the periodic table of elements is related to the number of outer electrons, that is, elements having the same attribute are arranged in the same family. For example, the number of outermost electrons of the first group element is 1, and the number of outermost electrons of the second group element is 2. But they are not always so perfectly matched.
1. Where should hydrogen be?
The number of electrons in the outermost layer of hydrogen is 1, so one can think that it should indeed be in this position, that is, in the first group, after lithium and sodium which also have only one outer electron. However, hydrogen is a gas, not a metal, so its properties do not match.
The outermost layer of hydrogen has only one electron, and it only needs to get an electron to reach a stable state. Therefore, it is a very active element. In this sense, it is more complex with the 17th element. Close, that is, a halogen element like chlorine. These elements only need to get an electron to reach a steady state. By its nature, hydrogen is closer to chlorine than lithium.
2. Why are mercury and gold so weird?
Mercury is liquid at room temperature. In this sense, it is completely different from the other members of Group 12, they are all solid metals.
In the periodic table, the more elements that follow, the more positively charged protons in the nucleus. This creates greater suction on the extranuclear electrons, meaning they must run faster and faster. According to Einstein's theory of relativity, this causes their actual mass to be much greater than the normal mass of electrons, thereby increasing the inward pull. Mercury emits electrons at speeds up to 58% of the speed of light, so tightly operated that they cannot be linked to other atoms and thus cannot become solid. The same reason explains why gold is gold, a unique color in metals: the relativistic effect changes the way electrons absorb light.
3.F zone problem
The third family has two elements that may belong to other places. Looking down the periodic table, an electronic layer of electrons forms a series of tracks, and each time an electron fills a track, it enters the next track. By the 57th element (镧), the electrons began to enter the new orbit, the F orbit. To reflect this, the periodic table of elements separates the elements that make up the F-zone at the bottom of the periodic table, leaving a gap in the third family.
The report said, however, scientists are still controversial about which elements of the F zone should be ranked first. Some chemists insist that the order should be determined by electronic ordering, that is, to maintain the current order, placing 镧 and 锕 in the far left of the F zone. Others believe that it is better to rank the rightmost 镥 and 铹 in the front according to chemical properties (such as atomic radius and melting point).
All of these problems have led some chemists to believe that the periodic table of elements needs to be redesigned.
Retired Canadian chemist Fernando Dufour has invented a 3D periodic table that looks like a Christmas tree.
Eric Sherri, of the University of California, Los Angeles, is one of those who advocate a radical revision of the Periodic Table of the Elements. He supported a more thorough modification: by placing all 30 elements of the F region between the current second and third families, the vertical column was changed from 18 columns to 32 columns. In this way, the atomic numbers in the periodic table can be consecutively arranged.
But Gilmore Restrepo of the Max Planck Institute for Mathematics in Germany tends to be another way. Given the increased understanding of chemical reactivity, he studied whether the chemical similarity of elements in the same cycle was the same as 150 years ago. His conclusion is that 镧 should belong to the third family - that is, not in line with the current order.
The report says that redesigning the periodic table may seem like a Don Quixote-style exploration, but it may soon become an urgent task. People have begun to look for element 119. It will be waiting for where it is and where it is placed in the periodic table.