• 3 months ago
Transcript
00:00our planet the earth is called blue planet because 70% of the earth's surface
00:07is covered with water so a big part of the environment is water even in the air
00:16water is present in the form of water vapors and water is present beneath the
00:23earth's surface too and that water is called underground water underground
00:30water is often used for agricultural municipal and industrial use by
00:37constructing tube wells now let's learn some properties of water water is
00:44colorless it has no shape of its own it takes the shape of the container it is
00:50poured into water has a fixed volume but not a fixed shape let's try to
00:59understand this that is if you have one liter of water it will remain one liter
01:07of water no matter in which container you keep it so its volume is fixed but
01:16it will take the shape of the container in which you keep it that is it does not
01:23have a fixed shape so water or any liquid has a fixed volume but not a
01:31fixed shape now let's see other properties of water water exists in
01:39nature in three different states it is liquid form solid form and gaseous form
01:49now let's learn it one by one first of all liquid form of water water that we
01:59see in water bodies water that we drink water that we use is all a liquid form
02:07of water solid form when water is cooled below a certain degree of
02:13temperature it freezes and that form of water is known as solid form of water
02:20ice snowflakes are all solid forms of water one of the solid forms of water is
02:29very interesting that is snowflakes now let's see some of the beautiful shapes
02:36of snowflakes if you look closely at snowflakes you will see very beautiful
02:43formations each and every snowflake has a unique shape even no two snowflakes
02:51are alike most snowflakes have six sides there are mainly three types of
03:01snowflakes known as a star dendrite and plate next time you see fluffy
03:11snowflakes drifting down from the sky don't forget to take a closer look at
03:16them now let's learn another form of water that is gaseous form of water water
03:27in the form of steam or vapors is the gaseous form of water now let's learn
03:34how one form of water changes to another one when we heat water some of the water
03:43changes into a gaseous state called steam and this change of liquid state of
03:51to gaseous state is called evaporation now let's see how the gaseous state of
03:59water changes back to a liquid state of water take a glass of hot water and now
04:08cover it with a lid now wait for a while now remove the lid and observe the side
04:16of the lid facing the hot water you will find tiny droplets of water on it this
04:24is the steam in the glass that converted back to water droplets so this is the
04:32process where steam of water or gaseous form of water changes to liquid form of
04:39water and the process is called condensation now let's see how the
04:46liquid form of water changes to a solid form of water when the water is cooled
04:54down to a certain temperature like zero degrees even below degree water changes
05:01to a solid form and this is called freezing now let's see how the solid
05:08form of water changes back to a liquid form of water when the solid form of
05:13water that is snow or the ice gets enough heat that its temperature rises
05:20above zero degrees it changes back to liquid form and the process is called
05:26melting now let's learn what is precipitation water falling from the sky
05:34as rain snow or hail is called precipitation rainfall snowfall hailstorms
05:44are all examples of precipitation so kids today we learned a lot of
05:52properties of water and also states of water