What is the primary atomic characteristic that mendeleev used to organize the periodic table?
a. atomic mass.
b. atomic number.
c. the number of neutrons in the nucleus.
d. the date an element was discovered.

Atomic mass is the primary atomic characteristic that Mendeleev used to organize the periodic table.

The atomic mass (ma) is the mass of an atomic particle, sub-atomic particle, or molecule. It is commonly expressed in unified atomic mass units (u) where by international agreement, 1 unified atomic mass unit is defined as 1/12 of the mass of a single carbon-12 atom (at rest).

The correct answer between all the choices given is the first choice or letter A. I am hoping that this answer has satisfied your query and it will be able to help you in your endeavor, and if you would like, feel free to ask another question.

show the wavelengths of a wave. show the crests of a wave.