The postulates of Dalton’s law are given below:

a) Atom can neither be created nor destroyed.

b) Atoms of different elements may combine with each other in a fixed simple whole number ratio to form compound atoms.

i. Which postulate of Dalton’s atomic theory is based on the Law of Definite Proportions?

ii. Which postulate of Dalton’s Atomic Theory is based on the Law of Conservation of Mass?

Selvi took a conical flask, put some ice cubes into it and closed it with a stopper. Then, she found the weight of the conical flask using a balance. Its weight was 150 g. After some time, ice started melting and turned into water. She weighed the flask again. The weight was 150 g. What inference would you draw from this experiment?

Kannagi, Goutam, David, and Saleem collected different samples of water from a well, a pond, a river and underground water. All these samples were sent to a testing laboratory. The test result showed the ratio of hydrogen to oxygen as 1:8.

a) What conclusion would you draw from the above experiment?

b) Which law of chemical combination does it obey?

Rani prepared carbon monoxide in the laboratory. It contained 15g of carbon and 20g of oxygen. Ram also prepared carbon monoxide but using another method. It contained 42.9% of carbon. Show that the data of Rani and Ram are in accordance with the Law of Definite Proportions.

Cathode rays fall on a small object between the cathode and the anode. A shadow of the same size and shape as that of the object is observed on the wall opposite to the cathode. What conclusion can you draw from the above statement regarding the properties of cathode rays?