Question

4. Examine the atomic mass starting from H and follow the ribbon up to # 118. Find any atomic mass that is out of order. Mendeleev only had atomic masses, what would have been his sequence? Knowing that S48 ErO 22 Day

Answer 1

There are actually 3 such cases.

First, argon has a higher atomic mass(40) than does potassium(39), but comes before it in the Table. In Mendeleev table Argon will come after Potassium.

Second, cobalt(59) has a higher atomic mass than nickel(58.5), and also appears before it in the Table. In Mendeleev periodic table nickel will come before Cobalt.

Third, tellurium(127.5) comes before iodine(127) yet has a higher atomic mass. In mendeleev periodic table, Iodine will come before tellurium.

Fourth, seaborgium (271) comes before bohrium (270). In mendeleev periodic table seaborgium will come after bohrium.

Fifth, Hassium (277) comes before meitnerium(276). In mendeleev table Hassium will come after meitnerium.

Sixth, Roentgenium (280) comes after Darmatadtium (281).

Seventh, Uut (284) comes after copernicium(285).

Eighth, Uup (288) comes after flerovium(289).

Ninth, Protactinium(231) comes after Thorium (232).

Tenth, neptunium (237) come after uranium (238).

Eleventh, Americium (243) comes after plutonium (244).