At the Time Dimitri Mendeleev Produced the First Periodic Table

Multiple Choice

At the time Dimitri Mendeleev produced the first periodic table of the elements, which of the following was not true?

A) There were a little more than 60 known chemical elements.
B) Chemists used the concept of atomic mass.
C) Chemists knew that each element had distinct chemical behaviors.
D) It was the mid-18th century.
E) There were one or two new discoveries of chemical elements each year.