All questions of The Building Blocks of Matter for Grade 9 Exam
Which of the following is an example of diffusion?- a)A droplet of ink spreading in a glass of water
- b)A ball rolling down a hill
- c)The bending of light as it passes through a prism
- d)The expansion of a gas when heated
Correct answer is option 'A'. Can you explain this answer?
Which of the following is an example of diffusion?
a)
A droplet of ink spreading in a glass of water
b)
A ball rolling down a hill
c)
The bending of light as it passes through a prism
d)
The expansion of a gas when heated
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Adaeze Igwe answered |
Explanation:
Diffusion is the process by which particles move from an area of higher concentration to an area of lower concentration. In the case of a droplet of ink spreading in a glass of water, this is a classic example of diffusion.
Key Points:
- When the ink is dropped into the water, the ink particles are initially concentrated in one area.
- As time passes, the ink particles spread out and mix with the water molecules, moving from an area of higher concentration (the droplet) to an area of lower concentration (the rest of the water).
- This movement of particles from an area of high concentration to low concentration is known as diffusion.
- Eventually, the ink particles will be evenly distributed throughout the water, showing the completion of the diffusion process.
Therefore, option 'A' (A droplet of ink spreading in a glass of water) is an example of diffusion as it demonstrates the movement of particles from an area of higher concentration to lower concentration.
What is the primary characteristic of molecules in gases?- a) They have a strong intermolecular force.
- b) They are free to move in all directions.
- c) They vibrate in fixed positions.
- d) They are closely packed together.
Correct answer is option 'B'. Can you explain this answer?
What is the primary characteristic of molecules in gases?
a)
They have a strong intermolecular force.
b)
They are free to move in all directions.
c)
They vibrate in fixed positions.
d)
They are closely packed together.
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Nclex Coaching Centre answered |
The primary characteristic of molecules in gases is that they are free to move in all directions. This freedom allows gases to expand and fill their containers, resulting in no fixed shape or volume.
Which scientist is known for the theory that matter is made up of tiny particles called molecules?- a) Acharya Kanad
- b) Isaac Newton
- c) John Dalton
- d) Albert Einstein
Correct answer is option 'C'. Can you explain this answer?
Which scientist is known for the theory that matter is made up of tiny particles called molecules?
a)
Acharya Kanad
b)
Isaac Newton
c)
John Dalton
d)
Albert Einstein
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Nclex Coaching Centre answered |
John Dalton is credited with proposing that matter is composed of tiny particles called molecules. His work laid the foundation for modern atomic theory, which is crucial in understanding the structure of matter.
What is Brownian motion?- a)The random movement of molecules in a fluid
- b)The movement of light waves through a medium
- c)The motion of electrons in an atom
- d)The vibration of a solid object
Correct answer is option 'A'. Can you explain this answer?
What is Brownian motion?
a)
The random movement of molecules in a fluid
b)
The movement of light waves through a medium
c)
The motion of electrons in an atom
d)
The vibration of a solid object
|
Deepak Iyer answered |
Brownian motion refers to the random movement of tiny particles or molecules in a fluid. It occ
What process describes the change of state from a liquid to a gas?- a) Melting
- b) Boiling
- c) Condensation
- d) Freezing
Correct answer is option 'B'. Can you explain this answer?
What process describes the change of state from a liquid to a gas?
a)
Melting
b)
Boiling
c)
Condensation
d)
Freezing
|
|
Nclex Coaching Centre answered |
Boiling is the process where a liquid changes into a gas, usually through heating. During boiling, the molecules gain enough energy to overcome intermolecular forces and escape into the gas phase.
Which state of matter has a fixed shape and volume?- a) Plasma
- b) Gas
- c) Solid
- d) Liquid
Correct answer is option 'C'. Can you explain this answer?
Which state of matter has a fixed shape and volume?
a)
Plasma
b)
Gas
c)
Solid
d)
Liquid
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Nclex Coaching Centre answered |
Solids have a fixed shape and volume due to the strong intermolecular forces that keep the molecules closely packed. This characteristic distinguishes solids from liquids and gases, which do not have a fixed shape.
Which of the following statements is true about atoms?- a)Atoms are made up of protons, neutrons, and electrons.
- b)Atoms always exist in the form of molecules.
- c)Atoms cannot combine to form compounds.
- d)Atoms cannot be broken down into smaller particles.
Correct answer is option 'A'. Can you explain this answer?
Which of the following statements is true about atoms?
a)
Atoms are made up of protons, neutrons, and electrons.
b)
Atoms always exist in the form of molecules.
c)
Atoms cannot combine to form compounds.
d)
Atoms cannot be broken down into smaller particles.
|
|
Deepak Iyer answered |
Atoms consist of protons, neutrons, and electrons. Protons and neutrons are located in the nucleus, while electrons orbit around the nucleus. Atoms can combine to form molecules, which are composed of two or more atoms bonded together.
Which of the following statements is true about gases?- a) They take the shape and volume of their container.
- b) They have a fixed volume and shape.
- c) Their molecules are closely packed.
- d) They are incompressible.
Correct answer is option 'A'. Can you explain this answer?
Which of the following statements is true about gases?
a)
They take the shape and volume of their container.
b)
They have a fixed volume and shape.
c)
Their molecules are closely packed.
d)
They are incompressible.
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Nclex Coaching Centre answered |
Gases take the shape and volume of their container because their molecules are very loosely packed and move freely in all directions. This property allows gases to fill any available space.
Capillarity is the phenomenon responsible for:- a)Water boiling at 100°C
- b)Mercury rising in a narrow tube
- c)The expansion of solids when heated
- d)The absorption of light by a transparent material
Correct answer is option 'B'. Can you explain this answer?
Capillarity is the phenomenon responsible for:
a)
Water boiling at 100°C
b)
Mercury rising in a narrow tube
c)
The expansion of solids when heated
d)
The absorption of light by a transparent material
|
|
Deepak Iyer answered |
Capillarity refers to the phenomenon of a liquid rising or falling in a narrow tube against the force of gravity. It is responsible for the rise of liquids, such as mercury, in capillary tubes.
Adhesion refers to the:
- a)Attraction between particles of the same substance
- b)attraction between particles of different substances
- c)Formation of a meniscus in a liquid
- d)Tendency of a liquid to minimize its surface area
Correct answer is option 'B'. Can you explain this answer?
Adhesion refers to the:
a)
Attraction between particles of the same substance
b)
attraction between particles of different substances
c)
Formation of a meniscus in a liquid
d)
Tendency of a liquid to minimize its surface area
|
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Deepak Iyer answered |
Adhesion refers to the attraction between particles of different substances. It is the force that causes substances to stick or cling to each other.
Which of the following is an example of cohesion?- a) Sugar dissolving in water
- b) Perfume spreading in a room
- c) Ice melting in a drink
- d) Water droplets forming on a leaf
Correct answer is option 'D'. Can you explain this answer?
Which of the following is an example of cohesion?
a)
Sugar dissolving in water
b)
Perfume spreading in a room
c)
Ice melting in a drink
d)
Water droplets forming on a leaf
|
|
Nclex Coaching Centre answered |
Cohesion refers to the attraction between similar molecules. An example is water droplets forming on a leaf, where water molecules are attracted to each other, creating a droplet shape due to cohesive forces.
Which of the following represents a state of matter that is found at extremely high temperatures?- a) Plasma
- b) Liquid
- c) Bose-Einstein condensate
- d) Solid
Correct answer is option 'A'. Can you explain this answer?
Which of the following represents a state of matter that is found at extremely high temperatures?
a)
Plasma
b)
Liquid
c)
Bose-Einstein condensate
d)
Solid
|
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Nclex Coaching Centre answered |
Plasma is a state of matter that occurs at extremely high temperatures, where electrons are separated from their nuclei, resulting in a mixture of charged particles. This state is commonly found in stars, including the sun.
What is the fundamental unit of matter?- a)Atom
- b)Molecule
- c)Cell
- d)Proton
Correct answer is option 'A'. Can you explain this answer?
What is the fundamental unit of matter?
a)
Atom
b)
Molecule
c)
Cell
d)
Proton
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|
Deepak Iyer answered |
The fundamental unit of matter is the atom. Atoms are the building blocks of all substances and cannot be further divided without losing their characteristic properties.
In which state of matter are the molecules most loosely packed?- a) Plasma
- b) Gas
- c) Liquid
- d) Solid
Correct answer is option 'B'. Can you explain this answer?
In which state of matter are the molecules most loosely packed?
a)
Plasma
b)
Gas
c)
Liquid
d)
Solid
|
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Nclex Coaching Centre answered |
Gases have the most loosely packed molecules, allowing them to move freely and occupy more space. This property makes gases highly compressible compared to solids and liquids.
The molecular theory can explain which of the following phenomena?- a)Brownian motion
- b)Gravity
- c)Magnetic attraction
- d)Nuclear fusion
Correct answer is option 'A'. Can you explain this answer?
The molecular theory can explain which of the following phenomena?
a)
Brownian motion
b)
Gravity
c)
Magnetic attraction
d)
Nuclear fusion
|
|
Deepak Iyer answered |
The molecular theory can explain Brownian motion, which is the random motion of particles in a fluid due to collisions with molecules. Brownian motion provides evidence for the existence of molecules and atoms.
What is the smallest unit of an element that participates in chemical reactions?- a) Atom
- b) Compound
- c) Molecule
- d) Element
Correct answer is option 'A'. Can you explain this answer?
What is the smallest unit of an element that participates in chemical reactions?
a)
Atom
b)
Compound
c)
Molecule
d)
Element
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Nclex Coaching Centre answered |
An atom is defined as the smallest unit of an element that can exist independently and participate in chemical reactions. Atoms combine in various ways to form molecules, which are the smallest units of matter that retain the properties of that substance.
Surface tension is the property of a liquid that allows it to:- a)Conduct electricity
- b)Expand when heated
- c)Form a curved surface
- d)Change color
Correct answer is option 'C'. Can you explain this answer?
Surface tension is the property of a liquid that allows it to:
a)
Conduct electricity
b)
Expand when heated
c)
Form a curved surface
d)
Change color
|
|
Deepak Iyer answered |
Surface tension is the property of a liquid that allows it to minimize its surface area and form a curved surface. It is caused by the cohesive forces between the molecules of the liquid.
What phenomenon is demonstrated when a drop of ink spreads in water?- a) Filtration
- b) Condensation
- c) Evaporation
- d) Diffusion
Correct answer is option 'D'. Can you explain this answer?
What phenomenon is demonstrated when a drop of ink spreads in water?
a)
Filtration
b)
Condensation
c)
Evaporation
d)
Diffusion
|
|
Nclex Coaching Centre answered |
Diffusion is the process where molecules move from an area of higher concentration to an area of lower concentration, resulting in the spreading of ink in water. This illustrates the constant movement of molecules in liquids.
What is the process of a solid turning into a liquid called?- a) Condensation
- b) Boiling
- c) Melting
- d) Freezing
Correct answer is option 'C'. Can you explain this answer?
What is the process of a solid turning into a liquid called?
a)
Condensation
b)
Boiling
c)
Melting
d)
Freezing
|
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Nclex Coaching Centre answered |
Melting is the process where a solid changes into a liquid upon heating. During melting, the energy supplied allows the molecules in the solid to overcome their rigid arrangement and move more freely.
Which of the following is an example of a physical change in matter?- a) Burning wood
- b) Ice melting into water
- c) Rust forming on iron
- d) Baking a cake
Correct answer is option 'B'. Can you explain this answer?
Which of the following is an example of a physical change in matter?
a)
Burning wood
b)
Ice melting into water
c)
Rust forming on iron
d)
Baking a cake
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Nclex Coaching Centre answered |
Ice melting into water is an example of a physical change because it involves a change in state from solid to liquid without altering the chemical composition of the water. Physical changes can often be reversed, unlike chemical changes.
What is the relationship between intermolecular forces and the properties of different materials?- a) The strength of intermolecular forces affects the rigidity and hardness of materials.
- b) Stronger intermolecular forces lead to softer materials.
- c) Weaker intermolecular forces result in harder materials.
- d) Intermolecular forces do not affect material properties.
Correct answer is option 'A'. Can you explain this answer?
What is the relationship between intermolecular forces and the properties of different materials?
a)
The strength of intermolecular forces affects the rigidity and hardness of materials.
b)
Stronger intermolecular forces lead to softer materials.
c)
Weaker intermolecular forces result in harder materials.
d)
Intermolecular forces do not affect material properties.
|
|
Nclex Coaching Centre answered |
The strength of intermolecular forces directly influences the rigidity and hardness of materials. For instance, materials with strong intermolecular forces, like metals, are often harder compared to those with weaker forces, such as chalk.
Cohesion is the:- a)Attraction between particles of different substances
- b)Force that holds molecules of a substance together
- c)Ability of a liquid to flow
- d)Change in the state of matter from solid to liquid
Correct answer is option 'B'. Can you explain this answer?
Cohesion is the:
a)
Attraction between particles of different substances
b)
Force that holds molecules of a substance together
c)
Ability of a liquid to flow
d)
Change in the state of matter from solid to liquid
|
|
Deepak Iyer answered |
Cohesion is the force that holds molecules of a substance together. It is responsible for the formation of drops, the surface tension of liquids, and the shape of liquid droplets.
What happens to the intermolecular forces when a substance is heated?- a) They become stronger and hold molecules tighter.
- b) They disappear completely.
- c) They weaken, allowing molecules to move apart.
- d) They remain unchanged.
Correct answer is option 'C'. Can you explain this answer?
What happens to the intermolecular forces when a substance is heated?
a)
They become stronger and hold molecules tighter.
b)
They disappear completely.
c)
They weaken, allowing molecules to move apart.
d)
They remain unchanged.
|
|
Nclex Coaching Centre answered |
When a substance is heated, the intermolecular forces typically weaken, allowing the molecules to gain energy and move apart. This change is key to processes like melting and boiling, where the state of matter changes.
In liquids, how does the space between molecules compare to that in solids?- a) Liquids have less space between molecules than solids.
- b) There is no difference in space between solids and liquids.
- c) Liquids have the same amount of space as gases.
- d) Liquids have more space between molecules than solids.
Correct answer is option 'D'. Can you explain this answer?
In liquids, how does the space between molecules compare to that in solids?
a)
Liquids have less space between molecules than solids.
b)
There is no difference in space between solids and liquids.
c)
Liquids have the same amount of space as gases.
d)
Liquids have more space between molecules than solids.
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Nclex Coaching Centre answered |
Liquids have more space between their molecules than solids do. This increased intermolecular space allows liquid molecules to move around each other, giving liquids their fluidity and ability to take the shape of their container.
What is the primary factor that differentiates solids from liquids?- a) The arrangement and movement of molecules
- b) The shape of the container
- c) The color of the substance
- d) The temperature
Correct answer is option 'A'. Can you explain this answer?
What is the primary factor that differentiates solids from liquids?
a)
The arrangement and movement of molecules
b)
The shape of the container
c)
The color of the substance
d)
The temperature
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Nclex Coaching Centre answered |
The primary factor that differentiates solids from liquids is the arrangement and movement of molecules. In solids, molecules are closely packed and vibrate in place, while in liquids, they are less tightly packed and can move freely.
What happens to the molecules in a solid when it is heated?- a) They compress
- b) They move freely
- c) They expand significantly
- d) They vibrate in their positions
Correct answer is option 'D'. Can you explain this answer?
What happens to the molecules in a solid when it is heated?
a)
They compress
b)
They move freely
c)
They expand significantly
d)
They vibrate in their positions
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Nclex Coaching Centre answered |
When a solid is heated, its molecules vibrate more vigorously in their fixed positions rather than moving freely. This increased vibration can lead to slight expansion, but the solid remains in its fixed shape.
Which of the following best describes the Kinetic Theory of Matter?- a) Matter is only made up of solids and liquids.
- b) Matter is composed of large particles that do not move.
- c) Matter has fixed properties and does not change.
- d) Matter is made of small particles that are always in motion.
Correct answer is option 'D'. Can you explain this answer?
Which of the following best describes the Kinetic Theory of Matter?
a)
Matter is only made up of solids and liquids.
b)
Matter is composed of large particles that do not move.
c)
Matter has fixed properties and does not change.
d)
Matter is made of small particles that are always in motion.
|
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Nclex Coaching Centre answered |
The Kinetic Theory of Matter states that matter is composed of small particles (atoms and molecules) that are always in motion. This theory helps explain the behavior of gases, liquids, and solids under different conditions.
How do molecules differ from atoms?- a)Molecules are made up of atoms bonded together.
- b)Molecules are smaller than atoms.
- c)Molecules cannot exist independently.
- d)Molecules have a positive charge.
Correct answer is option 'A'. Can you explain this answer?
How do molecules differ from atoms?
a)
Molecules are made up of atoms bonded together.
b)
Molecules are smaller than atoms.
c)
Molecules cannot exist independently.
d)
Molecules have a positive charge.
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Deepak Iyer answered |
Molecules are formed when two or more atoms chemically bond together. They are composed of atoms held together by chemical bonds. Atoms are the individual particles that make up molecules and can exist independently.
What occurs when a gas cools and turns into a liquid?- a) Sublimation
- b) Evaporation
- c) Condensation
- d) Melting
Correct answer is option 'C'. Can you explain this answer?
What occurs when a gas cools and turns into a liquid?
a)
Sublimation
b)
Evaporation
c)
Condensation
d)
Melting
|
|
Nclex Coaching Centre answered |
Condensation is the process that occurs when a gas cools and transitions into a liquid state. This process involves the loss of energy by gas molecules, allowing intermolecular forces to pull them closer together.
What term describes the force of attraction between different kinds of molecules?- a) Compression
- b) Adhesion
- c) Cohesion
- d) Diffusion
Correct answer is option 'B'. Can you explain this answer?
What term describes the force of attraction between different kinds of molecules?
a)
Compression
b)
Adhesion
c)
Cohesion
d)
Diffusion
|
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Nclex Coaching Centre answered |
Adhesion refers to the force of attraction between different kinds of molecules. For example, when glue bonds paper and glass, it is due to the adhesive force. This concept is crucial in understanding how different materials interact with each other.
Chapter doubts & questions for The Building Blocks of Matter - Physics 2025 is part of Grade 9 exam preparation. The chapters have been prepared according to the Grade 9 exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for Grade 9 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.
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