Matter

Petroleum

Reason — Matter is anything that has mass and occupies space. Petroleum is considered matter because it is a liquid substance that has mass and occupies space. Light, heat and sound have no definite mass and do not occupy space.

occupy space and have a definite mass

Reason — All kinds of matter occupy space and have a definite mass. However, only solids have a definite shape, not all forms of matter can change their states easily, and only solids and liquids have a definite volume. Hence, the other options are not correct.

volume

Reason — The space occupied by matter is called its volume. The greater the size of an object, the larger will be the space occupied by it.

mass

Reason — The quantity or amount of matter in an object is called its mass. The larger an object, the greater will be its mass.

Plastic

Reason — Plastic is a non-living man-made or artificial matter. It is produced artificially from natural matter. Whereas, coal, cotton and silk are natural matters.

Soap

Reason — Soap is made of fats or vegetable oil and alkali. Desk, chair and handle can be made from wood.

Natural Matter — Wood, silk, coal, water, cotton, fruits

Man-made Matter — Plastic, medicines, detergent, ceramic, glass, nylon

Anything that has mass and occupies space is called matter.

Two main types of matter :

1. Living matter — Matter that shows characteristics of life like growth, reproduction, response to stimuli, etc.,
   Examples : Humans, trees, etc.
2. Non-living matter — Matter that does not show characteristics of life. They do not grow, move or reproduce on their own.
   Examples: Plastics, cotton, etc.

Plants and animals are living matter as they have mass and they occupy space. They can grow, move and reproduce on their own and are also made up of atoms and molecules. So, they are considered as matter.

gas

Reason — Gas is state of matter that has neither a definite shape nor a definite volume. It can be compressed inside a small container and can also spread into a large space area.

air

Reason — In case of gases, the molecules hardly attract each other. They lie far apart from each other and hence, the intermolecular spaces are very large.

all of the above

Reason — In solids, molecules are closely packed with very less intermolecular space. This makes solids hard and difficult to compress, giving them a fixed shape and size. So, they cannot flow like liquids.

Nitrogen

Reason — Nitrogen is a gas. Gases diffuse very fast because the particles of gases have enough space between them which allows them to move freely and to mix up easily.

Mercury

Reason — The force of attraction between like particles or molecules is called cohesive force. Mercury, although a liquid, shows a strong cohesive force. Whereas, oxygen and hydrogen are gases and have the least cohesive force. Petrol has a cohesive force less than mercury.

1. Solids — Common salt, wax, stone, sugar, coal, butter, copper
2. Liquids — Milk, mercury, blood, coconut oil, kerosene
3. Gases — Oxygen, L.P.G, carbon dioxide

Matter is made up of extremely small particles called atoms.

A molecule is the smallest unit of matter which exhibits all the properties of that kind of matter and is capable of independent existence.

(a) Particles of matter are held together by a force of attraction that exists between them. This force is known as intermolecular force of attraction.

(b) Particles of matter have space between them which is called inter-particle or intermolecular space or gap.

(c) The force of attraction between like particles or molecules is called cohesive force. It is this force which holds the molecules of a matter together.

(d) The phenomenon of intermixing of particles of one kind with another kind is called diffusion.

(e) The zig-zag motion of particles suspended in a medium is called Brownian movement. It is named after the scientist Robert Brown.

All substances that can flow are called fluids. Both gases and liquids are fluids.
Examples: Water and oxygen.

1. Solid — A solid has a definite shape and a definite volume. Molecules in the solid state are packed very close to each other.

2. Liquid — A liquid has a definite volume but no definite shape. The molecules in liquids are less closely packed than solids.

3. Gas — A gas has neither a definite shape nor a definite volume.

In solids, the molecules are closely packed with negligible intermolecular space between them. There is a strong force of attraction between the molecules. This makes them hard so they cannot flow. However, liquids and gases have more intermolecular space between them compared to solids, so they can flow freely.

In case of gases, the molecules are hardly attracted to each other with very large intermolecular space. As a result, gases have neither a fixed shape nor a fixed volume. They completely fill up the space available to them.

When you spray scent in a room, its particles mix with air molecules and diffuse and gradually spread throughout the room.

Air is a gas, and its particles are widely spaced, offering very little resistance to movement. So we can easily walk through it.

In liquids, the molecules are not very closely packed. They are moderately attracted to each other giving it a definite volume. Thus, the intermolecular spaces are larger and the molecules are able to move freely. This makes a liquid to take shape of the container.

This is because sugar particles settle into the spaces between water molecules. This is a result of intermolecular spaces in liquids.

This is because of diffusion. Gases diffuse very fast because their particles move randomly and mix with each other, even without stirring.

This is because of diffusion. Liquid diffuse slower than gas, so when we add drop of red ink to a small amount of water in a glass, it will diffuse slowly into entire glass of water.

In solids, particles are tightly packed, making them denser than liquids and gases.

Blowing air increases the air pressure inside the bottle. The high pressure pushes the egg outward.

iodine

Reason — Iodine is a substance that directly change from from the solid state to gaseous state without passing through the liquid state. Iodine sublimes into a violet gas when heated.

oxygen

Reason — Oxygen can change from its gaseous state to its liquid state at lower temperature by the process called condensation or liquefaction.

melting

Reason — The process by which a substance changes from solid state to liquid state is called melting or fusion.

evaporation

Reason — The change of state of a liquid into vapour below boiling point is called evaporation. Evaporation takes place even at room temperature but it becomes faster on heating.

all of the above

Reason — Heating can cause a substance to change its physical state and may also bring about a chemical change. All three states of matter expand on heating, which is referred to as thermal expansion. Hence, all the options are correct.

Both A and R are true and R is the correct explanation of A.

Reason — A is true as wood is a substance, so it is matter.
R is true as anything that has mass and occupies space is called matter.

Therefore, Both A and R are true and R is the correct explanation of A is the correct option.

Both A and R are true and R is not the correct explanation of A.

Reason — A is true as intermolecular forces of attraction keep particles close to each other.
R is true as particles are always in motion due to their kinetic energy.

Therefore, Both A and R are true and R is not the correct explanation of A is the correct option.

Both A and R are true and R is the correct explanation of A.

Reason — A is true as when sugar dissolves, its particles fit into the spaces between water molecules, so the level does not rise noticeably.
R is true as intermolecular gaps between water molecules allow sugar particles to occupy space without increasing volume.

Therefore, Both A and R are true and R is the correct explanation of A is the correct option.

A is true and R is false.

Reason — A is true as molecules can exist freely and retain the properties of the substance.
R is false as an atom is actually smaller; molecules are made of two or more atoms.

Therefore, A is true and R is false is the correct option.

(a) Water is matter because it has mass and occupies space.

(b) Any matter which has a definite volume but no definite shape is called a liquid.

(c) Liquids and gases can flow.

(d) The molecules are at a greater distance in gases as compared to liquids.

(e) Water boils at 100°C.

(f) The physical state of a substance, which has neither fixed volume nor fixed shape is a gas.

(a) False
Correct Statement — Many substances like carbon dioxide, iodine, etc., can exist in solid, liquid, and gaseous states under suitable conditions.

(b) True

(c) False
Correct Statement — Gases have the largest intermolecular space. Solids have very tightly packed particles.

(d) False
Correct Statement — Evaporation is a slow surface-level process that occurs at any temperature, while boiling is a rapid, bulk process that happens at the boiling point.

(e) False
Correct Statement — Some solids like camphor, iodine, and dry ice undergo sublimation, changing directly from solid to gas without becoming liquid.

(f) True

(g) True

(a) Volume
Reason — Solid, liquid and gas are the states of matter, while volume is a property of matter.

(b) Stone
Reason — Water, fruit juice, air and milk are fluids and can flow, while stone is a solid and cannot flow.

(c) Wood
Reason — Iron, aluminium and gold are metals, whereas wood is a non-metal.

(d) Melting point
Reason — Freezing, condensation and evaporation are processes of state change, while melting point is a temperature, not a process.

(a) Liquid

(b) Solid

(c) Gas

(a) Evaporation

(b) Sublimation

(c) Melting

(d) Boiling or vaporisation

(a) Camphor and dry ice (solid carbon dioxide)

(b) Paper and sugar

(c) Stone and iron

(a) The process by which a substance changes from solid state to liquid state is called melting or fusion.

(b) The process by which a substance changes from a liquid state to vapour state on heating is called vaporisation or boiling.

(c) The process by which a substance in gaseous state changes into its liquid state is called condensation or liquefaction.

(d) The conversion of a solid substance into its vapour without undergoing liquid state on heating is called sublimation.

(e) The phenomenon of intermixing of particles of one kind with another kind is called diffusion.

(f) The fixed temperature at which a solid changes into a liquid at a given pressure is called its melting point.

(g) The fixed temperature at which a liquid starts changing into gaseous state is called its boiling point.

(h) The process by which a substance in gaseous state changes into its liquid state is called condensation or liquefaction.

(i) The change of state of a liquid into vapour below boiling point is called as evaporation.

(a) The process by which matter changes from one state to another and back to the original state, without any change in its chemical composition is called interconversion of states of matter.

(b) The two conditions for the interconversion of states of matter

1. Change in temperature
2. Change in pressure

The difference between Solidification and condensation is given below:

The difference between Melting and boiling is given below:

The difference between gas and vapour is given below:

The difference between miscible and immiscible liquids is given below:

The difference between vaporisation and evaporation is given below:

1. Change (interconversion) in states of matter — The process by which matter changes from one state to another and back to the original state, without any change in its chemical composition is called interconversion of states of matter.

2. Thermal expansion of the matter — All the three states of matter, i.e. solid, liquid and gas expand on heating. i.e. they increase in size, without changing their composition. This process is called thermal expansion.

3. Chemical change — A chemical change is where a substance is transformed into a new substance with different properties.

During the interconversion of states of matter, the physical state changes without any change in its chemical composition. Whereas, in a chemical reaction a substance is transformed into a new substance with different properties.

A liquid change into its gaseous state by the process of boiling or vaporisation.
As a liquid is heated, its particles start gaining energy and move more vigorously which increases the gaps between the particles and decrease the force of attraction. Ultimately, a liquid changes into gaseous state.

When we heat a metal ball for about 5-6 minutes, it expands. This shows that a solid substance expands on heating. When we cool a solid substance, it again contracts to its original size.

When a candle is lit, first, candle wax melts, then turns into vapour.The vapours react 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.

Two characteristics of a chemical change are:

1. It is is permanent change in which new substances are formed from the original substances.
2. The properties of the new substances are entirely different from those of the original substances.

(a) A — Metal ball
     B — Metal ring

(b) The purpose of this experiment was to show that a solid expands on heating and when it is cooled back down, it contracts back to its original size.

Across:

1. Mass
2. Sublimation
3. Condensation

Down:

4. Matter
5. Boiling
6. Melting

(a) Pebbles are solids, so particles are closely packed. They have strong intermolecular forces and a fixed shape. Therefore, pebbles can be stacked one over another.

(b) Water is a liquid, so particles have weaker intermolecular forces. They can move freely. Therefore, water flows through gaps and spreads on the floor.

(c) Water evaporates slowly into the air after it spreads across the floor.

(d) Gases can flow in all directions.