Is Matter Around Us Pure — Science STD 9 — Question

State the law of conservation of mass. Give one example to illustrate this law.

How many grams of magnesium will have the same number of atoms as 6 grams of carbon?
(Mg = 24u; C = 12u)

Raunak took 5 moles of carbon atoms in a container and Krish also took 5 moles of sodium atoms in another container of same weight.

1. Whose container is heavier?
2. Whose container has more number of atoms?

When a beam of sunlight enters a room through a window, we can see tiny particles X suspended in a gas (or rather a mixture of gases) Y which are moving rapidly in a very haphazard manner.

1. What could particles X be?
2. Name the gas (or mixture of gases) Y.
3. What is the phenomenon exhibited by particles X known as?
4. What is causing the movement of particles X?
5. What conclusion does the existence of this phenomenon give us about the nature of matter?

Tabulate the differences in the characterisitcs of states of matter.

Draw a labelled diagram of the fractional distillation apparatus used for separating a mixture of alcohol and water.

State the various postulates of Dalton’s atomic theory of matter.

How will you separate a mixture of common salt, sulphur powder and sand?

How will you separate a mixture of kerosene oil and water? Explain with the help of a labeled diagram

Compare all the proposed models of an atom given in this chapter.