How did Dmitri Mendeleev create the periodic table of elements?

already exists.

Would you like to merge this question into it?

already exists as an alternate of this question.

Would you like to make it the primary and merge this question into it?

exists and is an alternate of .

He lined them up according to their properties and other characteristics.

First, John Newlands looked at the atomic masses of the known elements. He noticed that elements with similar physical and chemical properties came in intervals of 8. (So the 1st, 8th and 15th element were similar.) He proposed this idea as a unifying principle of chemistry. But it didn't work very well - not all the elements matched up.

Mendeleev's contribution was to suggest that not all elements had been discovered yet. This was reasonable, because in those days a lot of new elements were being discovered. He rearranged the table so that it had gaps where he believed missing elements were. In fact, he was even confident enough to predict the properties of the missing elements. The risk paid off: Many of his predictions were uncannily accurate.

Since then there have been a few modifications. The missing elements have been discovered, as well as a whole new group not in Mendeleev's table (the noble gases). The lanthanides and actinides have been moved into their own part to save space. And it is now understood that the important number is not mass number but atomic number (in Mendeleev's time this distinction was not appreciated, since neutrons had not been discovered). But, on the whole, the table is the same today as it was when Mendeleev produced it.

We also have an understanding of why it is that this pattern exists. It is due to the number of electrons in the outer shell of electrons, as each group has a different number in its outer shell (for example, Sodium [Na] in group 1 has 1 electron in its outer shell while Oxygen [O] has 6 electrons in the outer shell). These also effect their reactivity and thus their characteristics (as mentioned before) due to the stability of different groups.
+ 49 others found this useful
Thanks for the feedback!
In Science

Dmitri mendeleev constructed the first periodic table which is?

Wich is the table based on the mass of the element rather the number of protons. Later studies created the new table wich was superior to the old one, describing isotpes bette (MORE)

Dmitri Mendeleev: Major Contributor to Science

Russian chemist Dmitri Mendeleev was born in a small village near Siberia in 1834. His primary field of study was chemistry, but he also contributed to physics and mathematics (MORE)

The Founding Father of the Periodic Table, Dmitri Mendeleev

Regardless of whether chemistry was your best subject or if it was your bane, everyone over the age of 10 is familiar with the formalization of the periodic table. The periodi (MORE)

Facts About the Periodic Table of Elements

The periodic table of elements is an organizational system used to keep track of all the known elements on earth. These are the elements that everything around you is composed (MORE)

Natural Elements in the Periodic Table

The periodic table contains 118 distinct elements, but not all of these elements are naturally occurring. Some of them only exist as a result of human experimentation. However (MORE)

The Periodic Table of Elements

Life is sustained by a number of chemical elements. They are responsible for the birth of planets and the evolution of cells to complex organisms. Everyone knows that without (MORE)

Images of the Periodic Table

The periodic table of chemical elements created by chemist Dmitri Mendeleev has been around since the year 1869. There have been many updated and refined images of the periodi (MORE)