Completion of Mendeleev’s current table

as if Robert M. Hazen, Ph.D., George Mason University

Dmitry Mendellev forced very similar groups in the vertical columns of each season. By increasing the weight, he organized the elements from left to right and from top to bottom. So he had a weight-based side-by-side arrangement. Scientists have easily accepted the concept of the current table, not only because it organizes much of what is known, but also because of some very predictable predictions about the unknown.

Current table of members.
Each column in the current table contains elements with similar characteristics. (Image: Mary and Shutterstock)

Prepare a current table

Dmitry Mendelev added lithium, sodium, potassium, and rubidium to one column to compile the current table. Beryllium, magnesium, calcium and barium are in another column. Chlorine, bromine, iodine, that would be in the third column, and so on. Therefore, sodium was next to magnesium, potassium was next to calcium, and so on. It also leaves gaps for those who appear to be lost.

In the fourth row, between calcium and titanium, there is one missing element – Scandium, element 21. It was discovered in 1876, just as Mendelev had predicted. There seems to be another gap in the carbon-guided column. The material below is silicone, and above the tin, it was empty. Germanium, element 32, was discovered in 1886, and filled that void. New entities continue to fill and expand the current table.

This is a copy of the video series The joy of science. Watch now on Wondrium.

New techniques to find the missing ingredients

Flame spectroscopy image in the laboratory.
Flame spacoscopes have been used to find many heavy objects. (Image: Rabbitmindphoto / Shutterstock)

Between 1863 and 1875, no new ingredients were discovered for more than a decade. The old electrolysis technique was pushed to the limit. Breathing analysis is no longer effective.

In the mid-1870’s and 1890’s, another element of the discovery was the development of a flame splashescope, in which elements were identified by their unique bright lines.

Each new element can be identified by a special fingerprint. Remember that each element has its own unique electron energy levels. Thus, each element has its own unique wavelength, which is emitted when heated to high temperatures, when electrons heat up and down.

And they can be used as a special line to identify those new elements. By the end of the 19th century, 57 to 71 more than two dozen abnormal substances had been discovered in this wayTh Century. These chemical elements are so similar in chemistry that they are constantly accumulated in the natural world. They all have very similar chemical properties but can be isolated using a flame.

William Ramsey and the discovery of unknown gases

Between 1895 and 1898, many inactive gases were discovered. And these discoveries were made by Scottish chemist William Ramsey, who lived from 1852 to 1916. They are sometimes called noble gases. These are very immovable and do not stick to anything.

They occur only in nature as neutral gas atoms. Mendeleev’s chart predicts that these elements are 2, 10 and 18. These are now known as helium, neon, and argon. These previously separated elements added a new column to the current table, and that column was added to krypton and xenon, which are part of these groups. By the way, Ramsey has won the Nobel Prize and many other awards for his work by adding a whole new column to the Mandel table.

Learn more about stage changes and chemical reactions.

Experiments to identify fluorine

Mendelev’s timetable was incomplete in other ways as well. Fluorine, a key element in many common minerals, especially calcium fluoride, should have been included. However, no one was able to exclude Floran, and this effort became a major challenge in the late 19th centuryTh Century – An attempt to identify fluorine to show what fluorine properties may be.

Mendeleev’s table provided some useful clues to the researchers. Florin was at the top of a column containing chlorine, bromine, and iodine. All of these are highly volatile metals, and they can be produced by electrolysis of sodium or calcium compounds. Current characteristics indicate that fluorine requires a very high voltage. It will be very responsive – a very, very dangerous substance.

Early attempts to identify fluorine by electric field were bad. They have caused injury and death to many chemists. Strong batteries can actually separate fluorine from calcium. For example, it may vary in calcium fluoride, fluoride, and fluorine. But gas is so responsive that it immediately attacks and destroys tissues.

Learn more about the properties of materials.

Henry Moisan

Image of Henry Moissan, professor of Sorbonne University.
Henry Moissa successfully identified fluorine gas. (Image: Bibliothèque interuniversitaire de Santé, License Ouverte / Public domain)

So by the end of the 19th century fluorine isolation became a big challengeTh Century. A.D. In 1886, after three years of hard work, the French chemist Henry Moissa discovered the substance. As he did before, a strong electric current flowed through the fluorine salt solution. And, of course, the fluorine gas leaked.

But what he did differently was that he built the entire device from fluoride, which is probably the only substance that contains fluorine gas, which is already filled with fluorine. He received the Nobel Prize for this work. And yet, he said that although he could do this, he probably took 10 years of his life trying to identify fluorine. It was a great chemical test, but the people who did it really paid off.

Common questions about completing Mendeleev’s current table

Q: How are the 57-71 elements found in the periodic table?

More than two dozen unusual ingredients, 57 to 71, in Of Current table, Attended the end of 19Th Century. They all have very similar chemical properties and can be isolated using flame photometry. Each element has a distinctive bright line.

Q: Why were the first attempts to identify fluorine failed?

Fluorine gas Early attempts to differentiate fluorine from electricity were awful. It has caused injury and death to many chemists.

Q: Who was Henry Moisan?

Henry Moissan was a French chemist who was finally able to safely identify fluoride and fill in the gaps. Of Current table. To do this, a strong electric current flows through the fluorine salt solution to release the gas. To prevent fluoride from reacting, he built the entire device out of fluoride.

Keep reading
Results of the Second Law of Thermodynamics
Understanding Entropy in Energy Terms
The concept of Entropy

Leave a Comment