Question

Differentiate between:

a) Dobereiner's Triads and Newland's Octaves

b) Groups and Columns

c) Atomic Radius - Group 1 and Atomic Radius - Group 7

d) Atomic Size - Group 1 and Atomic Size - Group 7

e) Metallic Characteristic down the group and Metallica characteristic across the period.

f) Non Metallic Characteristic down the group and Non Metallic Characteristic across the period.

Answer 1

According to trains when elements are arranged in the order of increasing atomic masses, groups of three elements, having similar chemical properties are obtained. The atomic mass of the middle element of the traid being equal to the arithmetic mean of the atomic masses of the other two elements.

According to octaves when elements are arranged in the order of increasing atomic masses, the properties of eighth element are a repetition of the properties of the first element.




Metallic character decreases across the period