• 3 months ago
Transcript
00:00Matter Everything around us.
00:06We know that there are thousands of things around us, made from different substances.
00:15Matter Anything that has mass and occupies space
00:23is called matter.
00:26We inhale the fresh air in the garden, quench our thirst with fresh orange juice, and enjoy
00:37delicious cakes that our mothers prepare.
00:43All these things are matter because they have mass and occupy space.
00:55Mass is the physical quantity or the actual amount of matter any object is made of.
01:09When your mother purchases a kilogram of mangoes from the market, then this one kilogram is
01:16the amount of matter in mangoes.
01:22Our body is made up of bones, tissues, and various fluids that constitute the mass of
01:31the body.
01:34We should not confuse mass with weight.
01:39Mass and weight are two different concepts.
01:44The mass of an object remains the same, but the weight changes.
01:51For example, the weight of an object, when measured on the moon, will be different from
01:57that on the earth, but the mass shall remain the same.
02:04STATES OF MATTER
02:07Matter is present all around us in some form or the other.
02:14It exists in three states, solid, liquid, and gas.
02:23Water is present in all the three states, solid, i.e., ice, liquid, i.e., water, and
02:33gas, i.e., water vapor.
02:38States are substances that are usually hard and have a definite shape and size.
02:47You can easily pick up an apple because it is a solid.
02:54It is possible to throw and catch a ball because it is a solid.
03:03You can keep and carry things in boxes or bags because they have a hollow space enclosed
03:12within solid boundaries.
03:16Solids are generally easy to pick, carry, or move around, except when they are huge.
03:28A pair of boots, a sweater, a burger, a fruit, a house, a car, etc. are some examples of
03:38solids.
03:43Solids can change their shape only when an external force is applied.
03:52Some solids are elastic.
03:57For example, rubber band.
04:00They stretch when pulled and return to their original shape when released.
04:10Liquids are substances that have a definite quantity, i.e., volume, but have no definite
04:19shape.
04:23Solids do not have their own shape, but take the shape of the container in which they are
04:31kept.
04:34We get water through water pipes and taps, and we store it in bottle.
04:44Solids flow and can be carried around only when they are filled in a container.
04:53Thick liquids such as honey flow a little slower than thin liquids such as milk.
05:05Liquids flow from an upper level to a lower level.
05:14Solids are substances that do not have any definite shape or size.
05:21The air we breathe and the air in hot air balloon are examples of gases.
05:30We cannot see air, but we do feel its presence when it blows.
05:39Solids spread out to occupy the whole space in a container.
05:46We can feel the presence of air against our skin or when we see kites flying in the sky.
05:57All living things need an important gas called oxygen to survive.
06:06It is one of the many gases present in the atmosphere that surround the earth.
06:15When layers of plants and animals buried in the earth are exposed to intense heat and
06:23pressure over thousands of years, natural gas is formed.
06:31There are other gases trapped inside the earth which are released when oil and coal
06:39are extracted from the earth's surface and also when volcanoes erupt.
06:49Gases are compressed in metallic cylinders for special uses like cooking gas or oxygen
06:58The three most important things for life are generally found in these forms- food in the
07:11form of solid, water in the form of liquid, air we breathe in the form of gas.
07:24MATTER- EVERYTHING AROUND US
07:31PROPERTIES OF MATTER
07:35We know now that everything around us is matter, whether natural or man-made, living or non-living.
07:52The actual material that any matter is made up of gives it properties like its shape and
08:00size, taste and color, etc.
08:06Substances made from the same material can look very different.
08:14For example, curd and cheese are made from the same material, milk, but look different.
08:25Things having the same weight may not occupy the same space, for example, half a kilogram
08:33of ice cream and half a kilogram of cotton.
08:41Let us study the properties of matter in detail.
08:48MATTER OCCUPIES SPACE
08:53Solids, liquids and gases may occupy space in distinct ways.
09:01We keep food grains in sacks.
09:07Fill the fuel tank of our vehicles with liquid fuel like petrol or diesel.
09:17And our bicycle tires have air filled in their tire tubes.
09:24MATTER HAS MASS
09:30Everything around us that has mass is matter.
09:37Mass is measured in grams and kilograms.
09:43Mass of matter can vary from light things like a shuttlecock to the mass of a cupboard
09:51that can weigh several kilograms.
09:58CHANGE OF STATE OF MATTER
10:01An important feature of matter is that it can change from one state to another.
10:11Water is a common example of matter that can exist in all three states.
10:21When water, i.e. liquid, is kept in the freezer, it becomes ice, i.e. solid.
10:31When this ice is heated or kept outside, it changes back into water, i.e. liquid.
10:41If the water is boiled, it changes into steam or water vapour, i.e. gas.
10:52When the steam or vapour cools down, it changes back into its liquid form, i.e. water.
11:04When your mother heats milk, i.e. liquid, adds sugar to it, i.e. solid, and keeps stirring
11:12it for a long time, you get yummy rubbery, which is partly solid.
11:23USES OF MATTER IN OUR LIVES
11:27All living things depend on various forms of matter to live.
11:37We eat food, i.e. either solid or liquid.
11:43Vegetables, fruits, pulses, and food grains are solids, while water, milk, different oils,
11:58etc. are liquids.
12:03Do not forget that the aroma of food is in the gaseous state.
12:11We live in homes that are built with bricks, stone, cement, etc. that are solids.
12:24Metals, ceramics, wood, etc. are used to manufacture things for our daily use.
12:37We wear clothes made from fabrics like cotton, silk, satin, etc., which are solids.
12:49Fuels such as petrol, diesel, etc. help us run our cars and buses.
12:59Air is filled in the tyres of cars and buses and other vehicles.