Matter In Our Sorroundings Flashcards
(21 cards)
Why is the rate of diffusion faster in gases?
The intermolecular force of attraction is minimum in gases.
In what ways are all substances around us matter?
All substances have mass and occupy space and are called matter.
Which property of gases helps us in detecting the leakage of LPG gas?
Diffusion.
Define boiling point.
The boiling point of a liquid is the temperature at which its pressure becomes equal to that of the atmosphere.
What are the characteristics of particles of matter?
Particles of matter:
- Have space between them.
- Are continuously moving.
- Can diffuse into one another.
- Attract each other.
- Have mass.
Ice and water are essentially the same substance. Mention two differences in their properties.
Ice: It is rigid and has a definite shape. It can be stored without a container.
Water: It is a fluid and has no definite shape. It can’t be stored without a container.
Solids are incompressible. Sponge is a solid, but it can be compressed. Why?
Some solids have vacant spaces in them. Sponge is a solid that has minute holes in which air is trapped. When we press it, air is expelled, and so we are able to compress it. When pressure is removed, air is trapped again in the minute holes.
State the characteristic of the gas used in supplying oxygen cylinders to hospitals.
Compressibility
Give reasons why naphthalene balls disappear over time without leaving any solid.
Naphthalene has the property of sublimation, so even at room temperature, it evaporates into vapor.
A gas exerts pressure on the walls of the container. Give reason.
The molecules of a gas are continuously moving at random, either striking among themselves or with the walls of the container. The pressure on the walls of the container is the force per unit area with which the moving gas particles strike per unit area of the containing vessel.
Why don’t wet clothes dry up easily during the rainy season?
During rainy days, the humidity of air increases; therefore, air is quite saturated with water vapor. Air cannot hold more water vapor. The rate of evaporation of water from wet clothes decreases. So, wet clothes dry slowly during the rainy season.
What clothes should we wear in summer? Why?
We should wear cotton clothes during the summer season because, during summer, we perspire more to maintain the temperature of our body. Cotton is a good absorber of water. It then exposes the water to the atmosphere for easy evaporation, leaving us dry and cool.
Why can we smell perfume from several meters away?
Perfume has a high degree of vaporization, and its vapors diffuse into the air easily. That’s why we can smell perfume sitting several meters away.
Give two reasons to justify that water at room temperature is a liquid.
Water at room temperature is a liquid because:
- It has fluidity and assumes the shape of the containing vessel.
- It has a melting point below room temperature and a boiling point above room temperature.
Give two reasons to justify that an iron almirah is solid at room temperature.
Iron almirah is solid because:
- It is rigid.
- It has a fixed shape.
What produces more severe burns: boiling water or steam? Why?
Steam produces more severe burns as compared to boiling water. Steam is more energetic than boiling water and can produce more severe burns.
Intermolecular force of attraction is maximum in:
Solids
Evaporation of a material takes place below its:
Boiling point.
Which process does not convert liquid into vapor?
Condensation
Gases are liquefied under:
High pressure and low temperature.
What decreases the rate of evaporation?
Humidity
