ICSE Class 9 Chemistry Chapter 5 Selina Concise Solutions - Free PDF Download
FAQs on Concise Chemistry Class 9 ICSE Solutions for Chapter 5 - The Periodic Table
1. What is a periodic table and its importance?
The periodic table is considered to be an important tool in the history of Chemistry. It represents the atomic properties of all the chemical elements present in it in a proper format which leads to the inclusion of atomic number, atomic mass, and the relationship between the elements. The elements which have got similar chemical properties are arranged properly in the columns in the periodic table. It is an organized array of chemical elements based on the increasing order of the atomic number. On Vedantu you can get free chapter wise solutions for every topic. Vedantu believes in making the learning process hassle free for students so they can access material just by one click, that too, for free.
2. What are elements and why do they need to be properly classified?
Elements are considered to be pure substances made up of one kind of atom and cannot be broken into simple substances. It is important to classify the elements properly. It makes it easier to study them in an organized manner because it is difficult to study the properties and the uses of each element in an isolated way. We are able to correlate the properties of elements with their fundamental properties of different states of matter and also define the relationship of one element with others.
3. How did Mendeleev arrange the elements in his periodic table and what is the basis of his classification?
Mendeleev has arranged the chemical elements in his periodic table. He had arranged these elements on the basis of the increasing order of the atomic weights of the element. In other words, his periodic table was arranged on the basis of the atomic masses of each element. They were arranged on the basis of horizontal rows(periodic) and vertical columns (groups). His basis of classification was mainly that the properties of elements are periodic functions of their atomic weights and the elements have got the same properties used to appear at the regular intervals.
4. What was missing from Mendeleev's original periodic table?
There were some elements that were missing from Mendeleev's periodic table. Mendeleev has arranged the chemical elements in his periodic table. He had arranged these elements on the basis of the increasing order of the atomic weights of the element. Anomalous pairs of elements like argon, cobalt, and tellurium were missing from Mendeleev's periodic table. There were a total of 63 elements in it and they were basically classified on the basis of their similarities in relation to the properties.
5. What are the merits of Mendeleev's classification of elements?
There are a lot of merits of Mendeleev's classification are mentioned below :
It generalized the study of the elements.
Mendeleev has left some gaps in his periodic table for the inclusion of those elements which are still unknown.
He had already predicted the properties of the unknown elements based on the properties of elements lying adjacent to the vacant slots.
He predicted the existence of elements such as gallium, scandium, and germanium which were unknown to everyone.
