We have excluded elements above 108 on this periodic table for the simple reason that the larger elements don’t really exist in the real world. The original periodic table of the elements published by Dimitri Mendeleev in 1869 arranged the elements that were known at the time in order of increasing atomic weight, since this was prior to. Weve talked about it in other videos, you could view this 12. Periodic Table of Elements with Relative Atomic Masses Periodic Table Key X Synthetic Elements X Liquids or melt at close to room temp. One molecule of water (H 2 O) would weigh 18.02 amu (2×1.00797 amu for H + 15.9994 amu for O), and a mole of water molecules would weigh 18.02 grams. You might find a table of elements showing element 115 or even 118 elements total. So if we first look at carbon, carbon, we see from this periodic table of elements, has a molar mass of 12.01 grams per mole. There is a Netflix documentary about this topic entitled Bob Lazar: Area 51 & Flying Saucers. The elements above 92 are strange, like for example element 115 that was reportedly found at Area 51. The parenthesis are a scientific way of saying this number is guesstimated, at best, and we really don’t know much about these elements because they are artificial and tend to disintegrate rapidly. Members of the group including of course nitrogen, along with arsenic, phosphorous, antimony and bismuth are particularly stable in compounds because they tend to form double or triple. You might note in the periodic table the mass numbers are in parenthesis for elements 93 and above. Arsenic, atomic number 33 lies in between phosphorus and antimony in group 15, the so called Nitrogen group of the periodic table. At least you won’t be finding any in this lifetime. As such, elements above 92 don’t really exist, except under special laboratory conditions. All elements above atomic number 92 are created artificially in laboratories, and generally they are extremely unstable and tend to disintegrate rapidly. As such, it’s highly unstable and unable to exist for very long. It is element 94, making it bigger than uranium. In 1940, a new element, plutonium, was created in a laboratory. Before the year 1940, it was believed that only 92 elements existed.
![periodic table of elements with molar mass periodic table of elements with molar mass](https://s3-us-west-2.amazonaws.com/courses-images-archive-read-only/wp-content/uploads/sites/887/2015/04/23211056/CNX_Chem_02_05_PerTable11.jpg)
(See the original work of Dmitri Mendeleev here.) At that time, scientists were still discovering new elements almost every year. The original table of the elements, credited to Dmitri Mendeleev in 1871, had only 56 elements. The table of elements shown here has 108 elements.