If we show a red litmus paper over ammonia gas. What change can be observed?

Show a wet red litmus paper on the mouth of the boiling tube. What change can you observe?

A student is doing an experiment in the laboratory using sodium. Suddenly, a piece of sodium falls into liquid ammonia. (a) What changes can you observe in liquid ammonia? (b) What is the reason for the change? (c) If the solution is kept for a long time it is changed into bronze colour. Why?

A student is doing an experiment in the laboratory using sodium. Suddenly, a piece of sodium falls into liquid ammonia. What change can you observe in liquid ammonia?

Teacher explained that due to a stoichiometric defect, the density of a crystal changes. What change can we observe?

Show wet blue and red litmus papers over the watch glass containing soap solution one by one. Which litmus paper shows a colour change ?

By passing chlorine gas through a colourless solụtion, we get bleaching powder. (a) What happens if CO_2 is passed instead of Cl_2 ? (b) When CO_2 is passed in excess, what changes can you observe?

The amplitude of a simple harmonic oscillation is doubled. What change will you observe in the following physical quantity of the oscillator? Maximum velocity.

The amplitude of a simple harmonic oscillation is doubled. What change will you observe in the following physical quantities of the oscillator? Period.