Matter in Our Surroundings (Class - IX)
Properties of matter including states, intermolecular forces, kinetic energy, and phase changes (melting, boiling, evaporation, sublimation) for Class IX students.
Questions
Which of the following substances has the highest force of attraction among its particles?
- Air
- Water
- Gel
- Stick
Which of the following influences intermolecular forces?
- Intermolecular space
- Radius of molecules
- Colour of the molecules
- Chemical properties of molecules
Which of the following cannot be a property of molecules of a substance?
- Small in size
- Variable in shape
- Possess kinetic energy
- Attract each other
Which of the following determines the physical nature of a chemical substance?
- Molecular weight
- Molecular motion
- Molecular shape
- Molecular reactivity
Which of the following has the highest force of attraction between its particles?
- Juice
- Bat
- Honey
- Methane
What is the force of attraction between similar particles called?
- Adhesion
- Cohesion
- Collision
- Fusion
What does melting point of a solid indicate?
- Randomness of its particles
- Strength of force of attraction between particles
- Kinetic energy of particles
- Inter molecular space between particles
What is the effect of heating on kinetic energy of molecules?
- Decrease in K.E.
- No effect
- Increase in K.E.
- May increase or decrease in K.E.
In which of the following are the particles vibrate about their mean position?
- Iron
- Water vapour
- Perfume
- Acid
Which of the following is responsible for definite shape of an iron ball?
- Strong forces of attraction between molecules of iron ball
- Large distance between the molecules of iron ball
- High speed of molecules of iron ball
- Random motion of molecules of iron ball
Dry ice at room temperature is converted into gas directly. What is this process called?
- Melting
- Vaporisation
- Condensation
- Sublimation
In which process is heat energy transformed into potential energy?
- Freezing
- Cooling
- Melting
- Boiling
How is the force of attraction between the particles of a liquid affected during evaporation process?
- The force of attraction remains unchanged.
- The force of attraction increases.
- The force of attraction decreases.
- The force of attraction first increases and then decreases.
Which of the following is a gas at room temperature?
- Water
- Dry ice
- Copper
- Alcohol
Which of the following processes can occur in the absence of heat?
- Melting
- Boiling
- Sublimation
- Vapourisation
What makes water to take the shape of the container in which it is poured?
- Weak forces of attraction between molecules
- Vibration of particles about their mean position
- Arrangement of particles in a definite manner
- Absence of space between particles
Which of the following has the weakest intermolecular forces between its particles?
- Gel
- Water
- Carbon dioxide
- Glass
Fragrance of perfume spreads rapidly in a room. What is the reason behind this phenomenon?
- High kinetic energy of particles of vapour
- Strong force of attraction among particles
- Large number of particles
- Lack of definite shape of gas particles
Which of the following does not have definite shape and volume?
- Mercury
- Methane
- Milk
- Marble
Which of the following has the highest kinetic energy in its particles?
- Oxygen
- Mercury
- Vinegar
- Bullet
Which of the following statements is not true about particles of oxygen?
- They have large intermolecular distance between them.
- They have negligible force of attraction between them.
- They vibrate around their mean position.
- They have high kinetic energy.
Which of the following is not true for boiling process?
- It is a rapid process.
- It takes place at the surface of a liquid.
- It takes place at definite temperature.
- It converts liquid into vapour.
Which of the following is true for evaporation?
- It occurs at all temperatures.
- It is a fast process.
- It occurs throughout the water body.
- It heats the surroundings.