Question

Reflections on Concepts
1. Newlands proposed the law of octaves. Mendeleeff suggested eight groups for elements in his
table. How do you explain these observations in terms of modern periodic classification?(AS)​

Answer 1

Explanation:

Answer: Yes, Dobereiner’s triads exist in the columns of Newland’s Octaves.

Example: In the Dobereiner’s triads Lithium, Sodium and Potassium make a triad, and these elements also present in the same column of Newland’s Octaves as these have same properties.

Answer 2

Answer:

Explanation:

● According to Newlands, every element starting from a given element resembles in its properties to that of the starting element ,when elements are arranged in ascending order of their atomic weights.

● According to Newlands, the properties of fluorine and chlorine are similar and sodium and potassium are similar same as packed is given by modern periodic table.

● Mendeleeff divided it into horizontal rows and vertical columns.He called them as periods and groups respectively. Modern Periodic table also shows the same.

● According to mendeleef the elements of same group have same properties. Modern Periodic Table also proposed the same thing.

● Mendeleeff gave the general formula for first group elements as R2O and the general for second group elements as RO. We can find the same thing in Modern Periodic Table.

● The elements of particular group possess same common valency same was proposed by Modern Periodic Table.