Selina Concise Class 6 Chemistry Solution Chapter No. 3- ‘Matter’ For ICSE Board Students
(1.) DEFINE MATTER.
ANS: – Anything that has mass and occupies space is called matter.
(2.) WHAT ARE THE TWO MAIN TYPES OF MATTER?GIVE TWO EXAMPLES FOR EACH TYPE.
ANS: – The two main types of matter are:-
i.) LIVING MATTER:- The earth is home to all kinds of plants and animals. They can grow, move and reproduction their own.
Examples:- Plant, Lotus, human etc
ii.) NON LIVING MATTER- most of the matter in the universe is non living. It means that it does not grow, move, reproduce on its own. It can be natural or manmade.
These are two types- a) Natural matter- wood, silk, water etc
b) Manmade matter- medicines, glass, steel etc.
(3) DIFFERENTIATE BETWEEN LIVING AND NON LIVING MATTER.
ANS: – The difference between Living matter and non living matter are-
a)The earth is home to all kinds of plants and animals. They can grow, move, and reproduce on their own. And in non living matter most of the matter in their universe is non moving. It means that it does not grow, move or reproduce on its own.
b) Living matter is natural only and non living matter can be natural or
(4) SELECT NATURAL MATTER AND MAN MADE MATTER FROM THE FOLLOWING:-
ANS: – NATURAL MATTER:- Wood, silk, water, coal, fruits.
MANMADE MATTER: – Plastics, medicines, ceramic, cotton, glass, nylon, detergents.
1) NAME THE SMALLEST PARTICLE FROM WHICH MATTER IS MADE UP.
ANS:- The smallest particle from which matter is made up is Atom.
2) WHAT ARE THE MOLECULES?
ANS: – Molecules are the smallest unit of matter. They exhibit all the properties of that kind of matter and is capable of independent existence.
3) GIVE ONE DIFFERENCE BETWEEN ATOMS AND MOLECULES.
ANS: – Atoms may or may not have independent existence while molecules have independent existence.
4) DEFINE- a) intermolecular force of attraction:- The molecules of matter are always in motion and attract each other with a force and this force is called intermolecular force of attraction due to which they are held together.
b) INTERMOLECULAR SPACE: – The molecules can move only when there are gaps or space between them. This space is called intermolecular space.
5) NAME THE THREE STATES OF MATTER AND VDEFINE THEM.
ANS: – The three states of matter are – 1. Solid state 2. Liquids 3. Gases.
SOLID STATE:- The molecules are very close to each other hence intermolecular spaces are small and intermolecular force is strong. Hence solid have definite volume, definite shape and incompressible .
LIQUIDS:- The molecules are less closely packed have more intermolecular spacs than solid, less stronger forces than solids.
Hence liquids have definite volume but no definite shape. They take the shape of container in which they are put.
GASES:- The molecules in the gases are for apart with weakest force of attraction. Hence gases have neither definite volume nor definite shape but easily compressible.
6) WHAT ARE FLUIDS? GIVE TWO EXAMPLES.
ANS:- Substances that can flow are called fluids. Both gases and liquids are fluids. Example- gases, liquids.
7) CLASSIFY THE FOLLOWING:-
a) SOLIDS:- Copper, Butter, Coal, Sugar, Stone, Wax, Common salt.
b) LIQUIDS:- Milk, Mercury, Blood, Coconut oil, Kerosene.
c) GASES:- Oxygen, Carbon dioxide, L.P.G
8) give reasons:-
a) LIQUIDS AND GASES FLOW BUT SOLIDS DO NOT?
ANS:- The molecules of liquids and gases are far apart, that is have more gaps, intermolecular attraction force is very less as compared to solids, hence liquids and gases can flow but solids do not have gaps in molecules is less and molecular force of attraction very strong.
b) A GAS FILLS UP THE SPACE AVAILABLE TO IT.
ANS:- Intermolecular force of attraction is least and intermolecular spaces are very large hence gases can fillup the spaces available to them.
c) THE ODOUR OF SCENT SPREADS IN A ROOM.
ANS:- Scent molecules being gases fill the spaces between air molecules and the molecules of air fill the spaces between scent molecules due to diffusion, fumes spread into a room.
d) WE CAN WALK THROUGH AIR.
ANS:- The molecules of air are far apart that is Large gaps and we can walk through in air easily.
e) LIQUIDS HAVE A DEFINITE VOLUME BUT NO DEFINITE SHAPE.
ANS:- The molecules of liquid are loosely packed and inter molecular force of attraction is small but number of molecules in it remain the same. Hence liquid have definite volume but no definite shape.
f) WHEN A TEASPOON OF SUGAR IS ADDED TO HALF A GLASS OF WATER AND STIRRED, THE WATER LEVEL IN THE GLASS REMAINS UNCHANCHED.
ANS:- When a teaspoon of sugar is added to half a glass glass of water and stirred, the water level in the glass remains unchanged because the sugar particles are adjusted between the water molecules as inter molecular gaps are more in liquids.
g) WHEN AN EMPTY GAS JAR IS INVERTED OVER A GAS JAR CONTAINING A COLOURED GAS, THE GAS ALSO SPREADS INTO THE EMPTY JAR.
ANS:-An empty jar is inverted over a gas jar containing a coloured gas , the gas also spreads into the empty jar Because gases can diffuse or flow in all directions.
h) A RED INK DROP ADDED TO A SMALL AMOUNT OF WATER IN A GLASS TURNS THE WATER RED IN SOME TIME.
Ans:- It is happened because when we put a drop of red ink in a glass of water, its particles diffuse with particles of water slowly but continuously and the water turns red.
a) COHESIVE FORCE:- The force of attraction between particles of the same substance is called cohesive force.
b) DIFFUSION:- The phenomenon of intermixing of particles of one kind with another kind is called diffusion.
c) BROWNIAN MOVEMENT:- The zig-zag motion of particles suspended in a medium is called Brownian movement.
10) WHY IS AN EGG KICKED OUT OF A BOTTLE WHEN AIR IS BLOWN INSIDE THE BOTTLE?
ANS:- When we invert the bottle and blow air into the bottle throw the side opening. It creates high pressure inside the bottles and the egg is kicked out of the bottle.
1) STATE THE THREE EFFECTS OF HEAT ON MATTER.
ANS:- The three effects of heat on matter are-
- Interconversion of states of matter.
- Thermal expansion of the substance
- Chemical change.
2)a) DEFINE INTERCONVERSION OF STATES OF MATTER.
ANS:- The process by which matter changes from one state to another and back to original state without any change in its chemical composition.
b) WHAT ARE TWO CONDITIONS FOR THE INTERCONVENSION OF STATES OF MATTER.
ANS:- The two conditions are- a. Change in temperature.
b.By applying pressure.
3) DEFINE THE TERMS-
a) FUSION:- The heating process by which a solid changes into the liquid state is called fusion.
b) VAPOURISATION:- The heating process by which a liquid changes into a vapour state is called vapourisation.
c) CONDENSATION:- The process by which a substance in gaseous state changes into its liquid state is called condensation.
d) SUBLIMATION:- The change of solid on heating to vapours directly and vice versa without passing through the liquid state is called sublimation.
e)DIFFUSION:- The phenomenon of intermixing or spreading of gaseous molecules is called diffusion.
f) MELTING POINT:-
g) BOILING POINT:- The fixed temperature at which a liquid starts changing into gaseous state is called its boiling point.The temperature remains constant till the whole of the liquid changes into gaseous state.
h) LIQUEFACTION:- Change of vapours on cooling to liquid is called liquefaction.
4) DIFFERENTIATE BETWEEN –
a) SOLIDIFICATION AND CONDENSATION
SOLIDIFICATION- The process of changing liquid into a solid state by cooling is known as solidification. Example- Water to Ice.
CONDENSATION:- The process of changing a gas or vapour state to liquid state by cooling is known as Condensation. example: Steam to water.
b) MELTING AND BOILING:-
MELTING:- The fixed temperature at which a solid changes into a liquid at given pressure is called its melting point. Example- Ice to water.
BOILING:- The fixed temperature at which a liquid starts changing into gaseous state is called its boiling point. Example- Water to Steam.
D) GAS AND VAPOUR:-
GAS:- The substance which remain in the gaseous state under normal conditions of temperature and pressure are called gases.
VAPOUR:- The process by which a substance changes from a liquid state to vapour state is called vapourisation or evaporation. Example- Water changes into a gaseous state on heating.
E) MISCIBLE AND IMMISCIBLE LIQUIDS:-
MISCIBLE:- Liquids which mix with each other are called miscible liquids. Example:- water and alchohiol
IMMISCIBLE:- Liquids which do not mix with each other are called immiscible liquids. Example- Water, oil.
5.) HOW IS INTERCONVERSION OF STATES OF MATTER DIFFERENT FROM CHEMICAL REACTION?
ANS:- During interconversion of state of matter composition of substance remains the same matter changes from one state to another state and back to the original state, while chemical reaction involves rearrangement of the molecular structure and composition changes.
6) HOW DOES A LIQUID CHANGE INTO ITS GASEOUS STATE? EXPLAIN.
ANS:- As a liquid is heated its particles starts gaining energy and move more vigorously which increases the gaps between the particles and decreasing the force of attraction. Ultimately a liquid changes into a gaseous state.
7) WATER CYCLE IS AN EXAMPLE OF INTERCONVERSION OF STATES OF WATER. EXPLAIN.
ANS:-Water from oceans , rivers, lakes from leaves of trees changes into vapours when temperature increases or evaporates and enters the atmosphere as clouds when temperature falls the vapous change into water and some of it in the form of snow fall on mountains and earth in the form of water and hales and this continues. Thus water cycle is an example of interconvertion of states of water.
8) WHAT HAPPENS TO A METAL BALL WHEN IT IS HEATED? WHAT DOES THIS SHOW?
ANS:- When a metal ball is heated it expands. This can be proved by an experiment. At first take a metallic ring and ball . Try to pass the metal ball through the ring. The ball is able to pass through the ring. Then heat the metal ball for 5-6 minutes. Then try to pass the ball through the ring but it cannot.
This shows that a solid expands on heating. Now cool the ball it again passes through the ring. This shows that a solid contacts on cooling.
9) WHY DOES A CANDLE BECOME SMALLER ON BURNING WITH TIME?
ANS:- On heating candle wax melts, then turns into vapours which reacts with air to produce two new substances, carbon-dioxide and water. Therefore a candle on burning becomes smaller and smaller and the part of wax which has undergone chemical change cannot be recovered.