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.

Question

Quizplus · Accepted Answer

The mid-18th century was well before Mendeleev's time and the development of the periodic table. The correct time period is the mid-19th century, when there were a little more than 60 known chemical elements, chemists used the concept of atomic mass, and knew that each element had distinct chemical behaviors. There were also one or two new discoveries of chemical elements each year, which necessitated the creation of a more organized system for classifying them.

At the Time Dimitri Mendeleev Produced the First Periodic Table