matter in our surroundings Flashcards
What is matter?
Anything which occupies space and mass is called matter.
What are the characteristics of the particles of the matter?
- Particles of matter have space b/w them.
- Particles of matter are continuously moving.
- Particles of matter attract each other.
- Particles of matter are very small.
What is diffusion?
The intermixing of particles of two different types of matter on their own is called matter.
What is K.E?
Energy possesed due to the motion of particles is called is K.E.
Write properties of solid state?
Solid has a definite volume, definite shape, have negligible compressibility and is rigid.
Sponge is a solid and still we are able to compress it. why?
It is because sponge has minute holes, in which air is trapped. When we press it, the air is expelled out from its holes making it highly compressible.
Rubber band changes is shape on stretching. Why is it salt?
This is because a rubber changes it’s shape under force and regains the same shape when the force is removed.
Write the properties of liquid state.
A liquid has a definite volume, no definite shape and cannot be compressed much.
How does aquatic animal breath under water?
The gas is from the atmosphere, especially oxygen and carbon dioxide diffuse and dissolve in water. The aquatic animals and plants can breathe underwater due to the presence of dissolved oxygen in water.
Write the properties of gaseous state.
A gas doesn’t have definitely volume and fixed shape. It has high compensibility
In the gaseous state how does its particles exert pressure?
In the gaseous state, the particles move about randomly at high-speed. Due to this movement, they hit each other and also the walls of the container. It causes gas to exert pressure.
What is the meeting point ?
The temprature at whicha solid melts to become a liquid at atmospheric pressure, is called its meeting point.
What is boiling point?
The temprature at which liquid starts boiling at the atmosphere pressure is known its boiling point.
Why temperature do not change during change
The temperature of substances remains constant at melting and bolling point until all the substances melt above because the heat supplied is continuously used in changing the state of substance by overcoming the force of attraction between the particles.
What is latent heat of fusion?
The amount of heat energy that is required to change 1kg of solid into liquid at its atmospheric pressure at its melting point is known as latent heat of fusion.
What is latent heat of vaporization?
The amount of heat energy that is required to change I kg of liquid into vapour state at atmospheric pressure at its boiling point is known as latent heat of vapourisation.
Why ice at 273 k is more effective in cooling thenwater at same temperature.
Ice at 273 k will teach latent heat from the medium to convert itself into water at 273k then into water but in case of water at 273 k, there will be no change in state and, it cannot take lantent heat from the medium. Hence ice will absorb more heat and causes more cooling.
Why steam causes more severe burn than boiling water at 100 C .
Steam contain more heat in the form of latent heat of vaporisation than boiling water. So when steam falls on the skin, it gives out extra heat as compared to water at same temperature and causes more severe burns.
What is sublimation?
The changing of state directly from solid to gas without changing into liquid sate is called sublimation.
What is dry ice?
Solid CO₂ gets covered directly into gaseous state on decreasing the pressure to 1 atmosphere without coming to liquid state. So solid CO₂ is stored under pressure and is called dry ice.
Define evaporation.
The process of changing liquid into vapor even below its boiling point is called evaporation.
Write the factors that affects evaporation.
- Surface area: If the surface area is increased, rate of evaporation increases.
- Temperature: With the increase of temperature, more no. of particles get enough K.E to go into vapour state. So rate of evaporation increases with increase of temperature.
- Humidity: Decrease in humidity increase the rate of evaporation. Humidity is the amount of water vapour present in the air.
- Wind speed: Increase in wind speed, increase the rate of evaporation.
How does evaporation causes cooling?
In evaporation only high energy particles leave the liquid surface. The particles of liquid absorb energy from the surrounding to regain the energy lost during evaporation. This absorption of energy from the surroundings makes the surrounding cool.
