Define groups. Answer - The vertical columns in the long form of the Periodic Table are called groups.

What was the drawback of the Law of Octaves? Answer - Law of Octaves failed to assign the position to the elements with large atomic...

State Newlands' Law of Octaves. Answer - Newlands' Law of Octaves states that "when elements are arranged in order of increasing atomic...

State Mendeleev's Periodic Law. [CBSE 2019] Answer - Mendeleev's Periodic Law states that, "The physical and chemical properties of the...

What was Dobereiner's basis of classifying elements? Answer - According to Dobereiner, elements having similar properties can be arranged...

Explain why, the direction of induced current in the coil of an A.C. generator changes after every half revolution of the coil. Solution....

A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is : (i) pushed into the coil ? (ii)...

Name two safety measures commonly used in domestic electric circuits and appliances. (NCERT Book Question) Answer. (i) Provision of...

What precautions should be taken to avoid overloading of domestic electric circuits ? (NCERT Book Question) Answer. (i) Too many high...

Q. A circuit has a fuse of 5 A. What is the maximum number of 100 W (220 V) bulbs that can be safely used in the circuit ? Solution....

How did nationalism develop through culture in Europe ? Explain. OR a “Culture played an important role in the development of nationalism...

(1) It abolished the feudal system that prevailed in many parts of Europe. (2) It established equality before the law. (3) Under this,...

Female figures become an allegory of the nation during the nineteenth century in Europe in the following ways: (1) Artists, in the...

Italy was unified after numerous struggles and movements as described below: (1) Italy had a long history of political fragmentation...

Conditions that led to the formation of the British nation state. (1) The Protestant movement which led to the formation of the Church of...

Before the eighteenth century, there were different ethnic identities with their own culture and politics - English, Welsh, Scots, or...

The role of Otto von Bismarck in the making of Germany is as follows: Nationalist feelings were widespread among middle-class Germans,...

Highlight any three measures and practices that French revolutionaries introduced to create a sense of collective identity among the...

Explain the mechanism of the cleaning action of soaps. Solution: There are so many impurities and dirt mixed in water, and most of all...

What change will you observe if you test soap with litmus paper (red and blue)? Solution: When we test soap with litmus paper colour of...