1. Name the three states of matter. Give one example of each.
2. What are the two ways in which the physical state of matter can be changed?
3. Explain how gases can be liquefied?
4. What is sublimation? Give examples.
5. Define latent heat of fusion.
6. Define latent heat of vaporization.
7. What produces more severe burns, boiling water or steam?
8. How can the boiling point of a liquid be rased, without adding any impurity?
9. In how many forms did the earlier scientists classify matter?
10. Why does a summer rainstorm lower the temperature?
11. A beaker of a liquid with a vapour pressure of 350 torr at 25°C is set alongside a beaker of water (Vapour pressure of 23.76 torr) and both are allowed to evaporate. In which liquid does the temperature change at a faster rate? Why
12. At a given temperature, one liquid has a vapour pressure of 240 torr and another measure 420 torr. Which liquid probably has the lower boiling point? Which probably has the lower heat of vaporization?
13. A drop of dettol got evenly distributed in water. How?
14. Liquid nitrogen is used as a commercial refrigerant to flash freeze foods. Nitrogen boils at -196°C. What is this temperature on the Kelvin temperature scale?
15. What property or properties of gases can you point to support the assumption that most of the volume in a gas is empty space?
16. What is unit cell?
17. What is the effect on surface tension of temperature?
18. Surface tension is same for different liquids. Explain.
Answers
Answer:
If you want the answers keep more marks cause those are 18 questions
Answer:
1. The three states of matter are Solid , Liquid and Gas.
SOLID - Wood , Table etc.
LIQUID - Water , Juice etc.
GASES - Hydrogen gas , Oxygen gas etc.
2. By Boiling
By freezing
3. There are three methods to liquify gases :
1. By compressing them at temperatures less than critical temperature.
2. By making gas to do some work against external force to change its state to liquids.
3. By generating volume , pressure and temperature in the gas .
4. Sublimation is the conversion of a solid into gas without coming to liquid state . For example : Dry Ice etc.
5. The heat required to change solid into liquid without changing temperature is called Latent heat of fusion .
6. The heat required to change solid into vapours is called Latent heat of Vaporization.
8. Steam produces more severe burns because steam has more heat energy than water because of Latent heat of Vaporization.
9. Three forms - Solid , Liquid and Gas.
10. In summer hot air rises up with humidity and heat , creating cold air at bottom giving rise to thunderstorms and lightning.
11. Beaker of water will evaporate faster.
12. Another measure
13. Because there is enough space in particles of matter .
14. 77 K
15.Gass have lower density than other states of matter .
16. Unit cell is the smallest group of atoms which forms a crystal and can reform a 3D structure .
17. When surface tension increases temperature decreases.
18.Surface tension is caused by attractions between liquid molecules and g
Different liquids have different attraction levels.
Explanation: