Long Form of Periodic Table

Author:V. K. Sally & R. Goel
10th CBSE
IMPORTANT

Long Form of Periodic Table: Overview

This topic explains the contribution of Neil Bohr in figuring out the limitations of modern periodic table. It also discusses how the periodic table was reconstructed into the long form of periodic table.

Important Questions on Long Form of Periodic Table

HARD
IMPORTANT

The elements A, B, C, D and E have atomic number 9,11,17,12 and 13 respectively. Which pair of elements belong to the same group?

MEDIUM
IMPORTANT

Give an account of the process adopted by "Mendeleev for the classification of elements". How did he arrive at the "Periodic Law"?

HARD
IMPORTANT

Which group of elements could be placed in Mendeleev’s periodic table without disturbing the original order? Give reason.

HARD
IMPORTANT

(i) State the law of octaves,
(ii) Name the scientist who framed the above law.
(iii) Two elements A and B obey the law of octaves. How many elements are in between A and B?

HARD
IMPORTANT

(j) What is the achievement of Dobereiner’s law of triads?

(ii) What were the reasons for rejecting this classification?

HARD
IMPORTANT

Cl, Li, Ca, Br, Na,Sr, I, K and Ba. From the list of elements given above make three triads and name the family of each triad,

MEDIUM
IMPORTANT

Why is there a necessity for the classification of elements? Give at least two reasons.