it is necessary to make a Periodic Table because it makes it easier to find elements that have similar physical characteristics and to find out the amounts of "shells" an element has of the amount of electrons on the elements vallence.
No, it is not necessary.
Iron (Fe)
Mendeleev supposed that a new row is necessary in the periodic table after the discovery of lanthanoides.
A Periodic table The Periodic Table of the Elements.
no - gases are few in number - metals make up most of the periodic table
Periods in the periodic table represent the number of electron shells necessary to fit all of the electrons. Once you fill the valence shell of an atom, the next electron must go in a new electron shell. This would constitute a new period on the periodic table.
No, Dmitri Mendeleev in Russia developed the first periodic table.
atomic number
There are 18 groups that make up The Periodic Table of Elements.
You dont
118 elements.
The answer is Group 17 Halogens.