(i) State the Heisenberg's uncertainty principle.
(ii) Write down the significance of Heisenberg principle.
(iii) Do you think it has utility in your daily life? Justify your answer

(i) What is the basis of classification to the classification of modern periodic table?
(ii) Can you apply the concept of periodic classification to the students in a class?
(iii) What is the value associated with it?

Ionic compounds have high melting and boiling points. There is strong electrostatic force of attraction between them. Answer the following:
(i) Why ionic solids are poor conductor of electricity?
(ii) What happens to the electrical conductivity when they are dissolved in water?
(iii) What is the value associated with it?

(i) What do you mean by diffusion?
(ii) Ammonia and hydrochloric acid gases are prepared at the two extreme corners in the laboratory. Which gas will reach first to a person in the centre of the laboratory?
(iii) Write down the value points

While working in laboratory a student kept ferrous sulphate in a vessel made up of zinc. After few days he found cracks in the container.
(i) Why cracks were found in the container?
(ii) Write down the chemical reaction takes place.
(iii) What is the value associated with this?