Lakhmir Singh Solutions Class 10 Chemistry Solutions for Exercise in Chapter 5 - Chapter 5 Periodic Classification of Elements

Question 58 Exercise

What is Dobereiner’s law of triads? Explain with the help of one example of a Dobereiner’s triad.


According to Dobereiner’s Law of triads, when elements are arranged in increasing order of their atomic masses, a group of elements with similar chemical properties is obtained. These are called triads. The atomic mass of the middle element is equal to the arithmetic mean of the atomic masses of the other two elements.

For example, Calcium, strontium, and barium have atomic masses of 40,088 and 137 forms a triad, and have similar chemical properties. The atomic mass of strontium is approximately equal to the average atomic masses of calcium and barium.

The arithmetic mean of atomic masses of calcium and barium = 40+137/2 = 88.5

Connect with us on social media!
2022 © Quality Tutorials Pvt Ltd All rights reserved