Question

In which of the following, elements are arranged in ascending order of their atomic numbers?

• A. Dobereiners law of triads
• B. Newland's law of octave
• C. Modern periodic table
• D. Mendeleev's periodic table

Answer 1

The Correct Option is C

Correct answer: Modern periodic table 

Explanation:
In the Modern Periodic Table, elements are arranged in the increasing order of their atomic numbers, which is the number of protons in an atom. This arrangement solves the limitations of earlier periodic laws and explains the periodicity of chemical properties more accurately. 

- Dobereiner's Law of Triads: Elements were grouped into triads based on similar properties, not strictly by atomic number.
- Newland's Law of Octaves: Elements were arranged by increasing atomic mass, not atomic number.
- Mendeleev's Periodic Table: Also based on atomic mass, not atomic number. 

Therefore, only the Modern Periodic Table follows the correct ascending order of atomic numbers.