(a) State the merits of Mendeleev’s classification of elements.
(b) Describe two anomalies of Mendeleev’s periodic classification of elements.
(a) The merits of Mendeleev's classification of elements are given below:
- Mendeleev's periodic law predicted the existence of certain elements such as gallium, scandium, and germanium, which were not discovered at that time.
- It could also predict the properties of various elements based on their position in the periodic table.
- It could place group 18 elements, called Noble gases in the periodic table when they were discovered.
(b) Anomalies of Mendeleev's periodic classification of elements are given below:
- Mendeleev's periodic classification of elements could not explain the position of isotopes in the periodic table. Since isotopes of the same metal have similar chemical properties but differ in their atomic masses. So, the isotopes of the same element should be given a different place in the periodic table as Mendeleev's periodic table was arranged in increasing order of their atomic masses. However, isotopes were not given a separate place in his periodic table.
- Mendeleev's periodic classification of elements could not assign a proper place for the element, hydrogen. As hydrogen resembles both alkali metals and halogens in some of the properties.
Related Articles
- What was the Mendeleev’s basis for the classification of elements?
- (a) State Mendeleev’s periodic law.(b) What chemical properties of elements were used by Mendeleev in creating his periodic table? (c) State any three limitations of Mendeleev’s classification of elements. (d) Besides gallium, which two other elements have since been discovered for which Mendeleev had left gaps in his periodic table ? (e) Which group of elements was missing from Mendeleev’s original periodic table?
- How could the modern periodic table remove various anomalies of Mendeleev’s Periodic Table?
- Classification of Elements.
- Classification of Circuit Elements
- Compare and contrast the arrangement of elements in Mendeleev’s Periodic Table and the Modern Periodic Table.
- Name two elements whose properties were predicted on the basis of their positions in Mendeleev’s periodic table.
- A part of the early classification of elements has been given below:H Li Be B C N OF Na Mg Al Si P S (a) Which law of classification of element is illustrated by the above arrangement of elements? (b) Name the scientist who proposed such a classification of elements. (c) Why is such a classification of elements compared with a characteristics of musical scale? (d) State one limitation of this classification of elements.
- Which group of elements could be placed in Mendeleev’s ′ Periodic Table without disturbing the original order? Give reason.
- State whether the following statement are true or false:(a) Newlands divided the elements into horizontal rows of eight element each. (b) According to Mendeleev’s periodic law, the properties of elements are a periodic function of their atomic numbers. (c) The elements in a group have consecutive atomic numbers.
- In Mendeleev’s periodic table, gaps were left for the elements to be discovered later. Which one of the following elements found a place in the periodic table later?GermaniumChlorineOxygenSilicon
- Use Mendeleev’s Periodic Table to predict the formulae for the oxides of the following elements: K, C, Al, Si, Ba
- Give an account of the process adopted by Mendeleev ′ for the classification of elements. How did he arrive at “Periodic Law”?
- Which of the following statement is correct in regard to the classification of elements ?(a) Elements in the periodic table are arranged on the basis of increasing atomic masses (b) Elements in Mendeleev’s periodic table are arranged on the basis of increasing atomic numbers (c) In modern periodic table, the element nickel of lower atomic mass is kept before the element cobalt of higher atomic mass (d) In modern periodic table, the isotopes of chlorine having diffrenet atomic masses are kept in the same group.
- (a) In the modem periodic table, which are the metals among the first ten elements?(b) What is the significance of atomic number in the modern classification of elements? Explain with the help of an example.
Kickstart Your Career
Get certified by completing the course
Get Started
Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies