CBSE - Class 9th - Science - Ch 4 - Structure of the Atom - Question Bank

Hey Friends, Hope you liked my previous post of Question Bank of Chapter 3 - Atoms and Molecules. In this post, I would like to share the questions from Chapter 4 - Structure of the Atom, to help you revise the concepts of this chapter to prepare well for exam.

CBSE - NCERT - Class 9th - Science

Chapter 4 - Structure of the Atom

• On rubbing two objects together, why does it get electrically charged?

• What are Canal rays?

• What is the mass of 1 proton and 1 electron?

• Explain Thomson’s model of an atom with Diagram.

• Explain the setup of Rutherford’s experiment involving Scattering of alpha (α) particles by a Gold Foil. 

• What were the observations made during the Rutherford's experiment of alpha particle scattering? Also Give the conclusions given by Rutherford for each of the observations.

• On the basis of Rutherford’s alpha (α) particles scattering experiment, what were the features of the Nuclear model of an atom as proposed by Rutherford?

• What were the drawbacks of Rutherford’s Model of Atom?

• What are the postulates put forward by Neils Bohr about the model of an Atom?

• Neutrons are present in the nucleus of all atoms, except one Element. Which one is that?

• What are the 3 rules followed for writing the number of electrons in different orbit or shells as suggested by Bohr and Bury?

• Draw the atomic structure showing orbit and electron distribution for
• Neon
• Sodium
• Argon

• What is the Valency of following elements
• Helium
• Neon
• Carbon
• Phosphorus
• Boron
• Aluminium
• Magnesium
• Fluorine

• Why is the Valency of Fluorine 1 instead of 7?

• Define Atomic Number.

• How is the Mass Number of Atom determined?

• Give the notation for representing an atom using atomic number, mass number and atomic symbol. Give an Example.

• Define Isotopes with an example.

• Derive the atomic mass of Chlorine containing 2 isotope of 35u and 37u in the ratio of 3:1.

• Give some examples of practical application of Isotopes in various fields.

• Define Isobars with examples.

• Who discovered Electron?

• Who discovered Proton?

Hope the above questions would help you prepare well for exams. If you are looking for answers to the above questions as well, do comment below and let me know your thoughts.

CBSE - Class 9th - Science - Ch 3 - Atoms and Molecules - Question Bank

Hi Friends, Hope you liked my previous question bank on Chapter 2 - Is Matter around Us Pure. In this post I would like to share a set of Questions from Chapter 3 - Atoms and Molecules.

CBSE - Class 9th - Science Book

Chapter 3 - Atoms and Molecules

• What are the 2 Laws of Chemical combination as established by Lavoisier and Proust? Explain each of them.

• What is an Atom?

• State the Postulates of Dalton’s Atomic Theory.

• What is IUPAC?

• What is the atomic Symbol of 
• Gold
• Iron
• Lead
• Potassium
• Silver

• Define Relative atomic mass of the atom of an element.

• What is the atomic mass of 
• Carbon
• Oxygen
• Chlorine

• What is a Molecule?

• What is Atomicity? What is the atomicity of 
• Oxygen
• Phosphorus
• Sulphur

• What is a compound? Give 2 examples with its constituents.

• What is an Ion? 

• What are the 2 types of Ions? 

• Give few examples of Ionic Compounds.

• What is Valency?

• Name few elements which show more than One Valency.

• Derive the formulae of below compounds with diagram depicting valency exchange:
• Hydrogen Sulphide
• Calcium Oxide
• Sodium Nitrate
• Calcium Hydroxide

• What is the difference between Molecular Mass and Formula Unit Mass? Give Example and explain.

• Define One Mole. What is the number of particles present in 1 mole of any substance?

I would request you to work on the Important numerical involving Molecular Mass, Mole, etc to stay more prepared for exams.

Would you like to have solutions for the above questions? Let me know your thoughts by commenting below.

All the Best for Exams!

CBSE - Class 9th - Science - Ch 2 - Is Matter Around Us Pure - Question Bank

Hey friends, Read the post to find a list of questions to help you revise your concepts and stay prepared for the exams.

CBSE NCERT - Class 9th - Science Book 

Chapter 2 - Is Matter Around Us Pure.

• When is something said to be a Pure substance?

• What is a mixture?

• What is a Homogeneous mixture or solution?

• What is a Heterogeneous mixture or solution?

• What is an Alloy?

• What is a solution?

• Describe the two components - Solvent and Solute.

• What are the properties of a solution?

• What is a saturated solution?

• What is an Unsaturated solution?

• Define Concentration of a solution.

• What is a Suspension?

• What are the properties of a Suspension?

• What is a Colloidal Solution?

• What is Tyndall Effect?

• What are the properties of a Colloid?

• What is Dispersed phase and Dispersing Medium

• What is Centrifugation? Mention some of its applications.

• Explain Sublimation process.

• What is Chromatography? Mention some of its applications.

• Explain the process of Distillation.

• What is Fractional Distillation?

• Explain the process of Separating the compounds of air with diagram

• What is Crystallization? Mention some of its applications.

• Explain the process of Water Purification System in Cities with a Diagram

• What are the 2 different types of Pure Substances?

• Explain the properties of Metals, Non-metals and Metalloids with examples.

• What is a compound?

• Give the difference between Mixtures and Compounds.

Hope you would find it useful for your concepts revision. If you are looking for solutions also, do comment below and let me know your thoughts

CBSE - Class 9th - Science - Ch 1 - Matter in Our Surroundings - Concepts

Let us study some concepts in a Question And Answers way.

CBSE NCERT Book - Class 9th - Science - Chapter 1

MATTER IN OUR SURROUNDINGS

• What is a Matter?

Ans: Anything in this universe which occupies space and have mass is a Matter. In other words, they have both Volume and Mass.

• In Earlier times, Indian Philosophers classified Matters in the form of 5 basic elements. What are they?

Ans: Air, Earth, Fire, Sky and Water. They are also known as "Panch Tatva".

• What are the Characteristics of "Particles of Matter"?

Ans: 

1. Particles of Matter have space in between them.
2. Particles of Matter are continuously moving.
3. Particles of Matter attract each other

• What is Diffusion?

Ans: Intermixing of Particles of two different types of matter on their own is called diffusion. Example - Diffusion of Ink with Water in the glass. Diffusion of Potassium Permanganate crystal in a glass of hot water.

• On Heating, Kinetic Energy of particles?

Ans: On Heating, Kinetic Energy of particles increases. This is because, Particles of matter are continuously moving and they possess Kinetic Energy. As the temperature rises, particles move faster. Thus we can conclude that with increase in temperature, kinetic energy of particle also increases.

• What are the 3 different states of Matter? Give basic Difference.

Ans: 

1. Solid - Fixed Shape, Fixed Volume
2. Liquid - No fixed Shape, but have Fixed Volume.
3. Gas - No fixed Shape, No fixed Volume

• Arrange the states of Matter in the order of higher diffusion rate to lower diffusion.

Ans: (Higher Diffusion) Gas > Liquid > Solid (Low Diffusion rate)

• When a solid melts, why does its temperature remain the same?

Ans: When the ice melts, temperature of the system does not change till the melting point is reached. This happens because when we continue to supply heat, the heat gets used up in changing the state of matter by overcoming the forces of attraction between the particles. The heat energy is getting absorbed by ice and its known as latent heat since it is hidden into the content of the beaker.

• What is a Melting Point?

Ans: The minimum temperature at which a solid melts to become a liquid at the atmospheric pressure is called its Melting point.

Example - Melting point of Ice is 273.15 K (K - Kelvin).

• What is Latent Heat of Fusion?

Ans: Amount of heat energy that is required to change 1 Kg of a solid into liquid at atmospheric pressure at its melting point is called as its latent heat of fusion.

• What is Boiling Point?

Ans: The temperature at which liquid starts boiling at atmospheric pressure is known as boiling point.

• What is Latent heat of vaporisation?

Ans: Amount of heat energy that is required to change 1 Kg of liquid into gas at atmospheric pressure at its boiling point is called as its latent heat of vaporisation.

• What is Sublimation?

Ans: A change of state directly from solid to gas without changing into liquid state is known as sublimation. 

Example - Sublimation of Ammonium Chloride on being heated.

• What is Deposition?

Ans: Direct change of gas to solid without changing into Liquid is called deposition.

• How can we liquefy gases?

Ans: Gases can be liquefied by applying pressure and reducing temperature.

• What is Evaporation?

Ans: Phenomenon of change of a Liquid into vapours at any temperature below its boiling point is called Evaporation.

• What are the factors affecting Evaporation?

Ans: Rate of Evaporation increases with:

1. Increase in Surface area.
2. Increase of temperature.
3. Decrease in Humidity.
4. Increase in Wind temperature.

• How does evaporation cause cooling?

Ans: When in an open vessel, water keeps evaporating. During this process, the particles of Liquid absorb energy from the surrounding to regain the energy lost during evaporation. This absorption of energy from the surrounding area makes the surroundings cool.

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