Chapter-7 Particulate Nature of Matter — Online MCQ Test
SCIENCE · Grade 8 · CBSE(NCERT)
Practice Chapter-7 Particulate Nature of Matter with a free chapter-wise online MCQ test.
This chapter covers: atoms - molecules - states of matter - intermolecular force - intermolecular space - sublimation.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter-7 Particulate Nature of Matter — Important Questions & Answers
What is the smallest unit of matter that retains the properties of an element?
- A. Molecule
- B. Atom
- C. Electron
- D. Compound
Answer: B. Atom
An atom is the smallest unit of an element that retains all the chemical properties of that element.
An atom is the smallest unit of an element that retains all the chemical properties of that element.
Which of the following best describes a molecule?
- A. A single atom of any element
- B. Two or more atoms bonded together
- C. A charged particle
- D. The nucleus of an atom
Answer: B. Two or more atoms bonded together
A molecule is formed when two or more atoms combine together through chemical bonds.
A molecule is formed when two or more atoms combine together through chemical bonds.
Why do gases exert pressure on the walls of a container?
- A. Because gas particles are stationary
- B. Because gas particles move rapidly and collide with the walls
- C. Because gases are denser than liquids
- D. Because gas particles stick to the walls
Answer: B. Because gas particles move rapidly and collide with the walls
Gas particles move randomly at high speed and continuously collide with container walls, creating pressure.
Gas particles move randomly at high speed and continuously collide with container walls, creating pressure.
Compare the intermolecular spaces in the three states of matter. Which arrangement is correct?
- A. Solid > Liquid > Gas
- B. Gas > Liquid > Solid
- C. Liquid > Solid > Gas
- D. All states have equal spaces
Answer: B. Gas > Liquid > Solid
Gases have the largest intermolecular spaces, followed by liquids, with solids having the smallest spaces between particles.
Gases have the largest intermolecular spaces, followed by liquids, with solids having the smallest spaces between particles.
A solid compound has a sublimation point below room temperature but hasn't sublimed in a closed container. The most logical reason is:
- A. The sublimation point is incorrect
- B. Sublimation has reached equilibrium; vapor pressure equals atmospheric pressure
- C. The compound is no longer solid
- D. Sublimation cannot occur in containers
Answer: B. Sublimation has reached equilibrium; vapor pressure equals atmospheric pressure
In a closed container, subliming particles accumulate as vapor until equilibrium is reached where vapor pressure equals the rate of sublimation.
In a closed container, subliming particles accumulate as vapor until equilibrium is reached where vapor pressure equals the rate of sublimation.