Question

Which of the following periodic classifications is not based on the atomic weights of elements?

• A. Dobereiner's law of triads
• B. Newlands law of octaves
• C. Mendeleev periodic table
• D. Modern periodic table

Answer 1

The Correct Option is D

Dobereiner's law of triads : This classification is based on the atomic weights of elements. Dobereiner grouped elements into triads where the atomic weight of the middle element was approximately the average of the other two.

Newlands' law of octaves : This also used atomic weights, classifying elements into groups of eight, similar to the octaves in music, where every eighth element had similar properties.

Mendeleev's periodic table: Mendeleev’s periodic table was originally based on atomic weights and he arranged elements in order of increasing atomic weight, recognizing that elements with similar properties occurred at regular intervals.

Modern periodic table : The modern periodic table is based on the atomic number (number of protons), not atomic weight. This is a key difference from the older classifications.

The correct option is (D): Modern periodic table