Matter - Phase Changes
Transcript
00:00Hi kids! Today we will learn changing states of matter. So let's get started.
00:10Kids, we know everything around us is made up of one or the other form of matter.
00:19And the three states of matter are solids, liquids, and gas.
00:29Gases have no specific shape, no specific volume, and no specific mass.
00:39Liquids have fixed volume, fixed mass, but no specific shape.
00:47And solids have specific mass, shape, and volume.
00:55Now let's see how one phase of matter changes to another state.
01:03Here we have some ice. Ice is in which state of matter?
01:11It is solid state of matter. But when it's heated, it changes into water, which is liquid state of matter.
01:24So melting changes solid state of matter into liquid state of matter.
01:31Now when water is further heated, it changes into water vapors, which is gaseous form of matter.
01:44So we learned heating, then ice changes ice to water, that is solid state to liquid state.
01:56And heating water changes water to water vapors, that is liquid state to gaseous state.
02:07You can also convert them back. Let's see how.
02:13If you cool down steam, steam changes into water, that is gaseous state to liquid state.
02:25And cooling down water changes it into ice, that is liquid changes into solid state of matter again.
02:39Let's see it with an experiment.
02:43Take a glass of hot water from which steam is coming out.
02:50Now place a lid to cover it and put some ice on the lid.
02:57This ice will cool down the steam and the steam changes back to tiny drops of water that you can see on the lid.
03:11Another easy experiment is take a chilled glass of water or any drink you like.
03:22What you see after some time, there are tiny droplets of water outside the glass.
03:31How and from where do they appear?
03:38Let's learn.
03:40There are always some water present in air in the form of gas.
03:47And when this air comes in contact with a very cold glass, the vapors in air cools down and changes into water again.
04:01Now we know how gas changes into water.
04:07Now we all know if we cool down water or freeze it, water again changes into ice.
04:17So when one state of matter changes to another state of matter, it is called phase change.
04:28Melting, freezing, evaporation, condensation are all phase changes.
04:43Conversion of a solid into water.
04:47Example, ice changing into water is called melting.
04:56Melting happens when a solid absorbs some heat.
05:02Heat gives energy to particles in solids and they start moving faster and slide around each other and the solid melts.
05:16As we know, in solids particles cannot move and slide around each other.
05:24But in liquid they can.
05:27And because of the heat they get, they start moving.
05:33And we say solids changed to liquid.
05:41Conversion of water into ice is called freezing.
05:46Freezing is also called solidification.
05:51And this happens when heat is released from the liquid.
05:56And as a result, particles slows down as they cannot move.
06:02And this liquid changes into solids.
06:11Conversion of liquid into gas is called evaporation.
06:17That is, heating water produces steam.
06:22What actually happens is, heating a liquid gives more energy to particles of liquid, which starts moving even faster, which is the characteristic of gas.
06:38So liquid turns into a gaseous state.
06:44Condensation.
06:47Conversion of gas into liquid is called condensation.
06:54Appearance of tiny droplets of water outside the glass of chilled drinks is an example of condensation.
07:07Condensation happens when heat is released from a gas.
07:12And the particle slows down, like the particles in a liquid.
07:18So kids, today we learned about phase changes.
07:24Now you may go ahead and take a quiz to learn more.
07:28Bye-bye!