Question

Mendeleev corrected the atomic weight of:

• A. $Be$
• B. $In$
• C. $Os$
• D. all of the above

Answer 1

The correct option is D all of the above

Mendeleev arranged the then known elements in increasing order of their atomic weight and observed the periodicity of properties of elements . Using the concept of valency he calculated atomic mass using the formula atomic mass = equivalent weight $\times$ valency . Thus he changed the atomic weights of $Be,In$ and $Os$.