In which year did AEB de Chancourtois organise the elements by atomic weight, by graphing the elements around a cylinder with a circumference of 16 units, corresponding to the weight of oxygen (O) ?

1862

The correct answer is option 1. 1862.

A.E.B. de Chancourtois, a French geologist, organized the elements based on their atomic weights and created the first attempt at a periodic table in 1862. His method involved arranging the elements along a helix or cylinder, which he called the "telluric screw." The circumference of the cylinder was set to be 16 units, which corresponded to the atomic weight of oxygen.

Despite his insightful attempt, de Chancourtois's work did not gain widespread recognition during his time. The significance of his periodic arrangement became more evident with the later development of Dmitri Mendeleev's periodic table in 1869 and, subsequently, the modern periodic table that followed.