Class :-ix
CHAPTER 2 Is Matter Around us Pure
TRUE/FALSE
1. Boiling is a bulk phenomenon.
2. Plasmas are all made of the same ions. They have different colours due to different amounts of electricity
3. Evaporation is a surface phenomenon.
4. A system that changes from a solid state to a liquid state gains energy.
5. The rate of evaporation depends only on the surface area exposed to the atmosphere.
6. You may find plasma in a star.
7. Latent heat of vaporisation is the heat energy required to change 1 kg of a liquid to gas at atmospheric pressure at its melting point.
8. If we pour liquid nitrogen (l ) N2 into a glass, it will change its state to a solid. Ans : False
9. Water at room temperature is a liquid.
10. Evaporation and boiling are the same processes because molecules move from a liquid to gaseous state. Ans : False
11. Atoms in a liquid are farther apart than the atoms in a gas.
12. It is just as easy to compress a liquid, as it is to compress a gas.
13. The molecules in a gas are in constant motion.
14. Because electrons have been stripped away from atoms in plasma, plasmas have a negative charge. Ans : False For more fi les visit
15. Gases present in air have the same pressure throughout the entire atmosphere.
16. All materials move from solid to liquid to gas as the temperature increases