Chapter 8: Journey Inside the Atom — Online MCQ Test
SCIENCE · Grade 9 · CBSE(NCERT)
Practice Chapter 8: Journey Inside the Atom with a free chapter-wise online MCQ test.
This chapter covers: Atom Electron Proton Neutron Thomson Model Rutherford Model Bohr Model Atomic Structure Nucleus Electron Shell Subatomic Particles Exploring atomic structure historical models and....
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Chapter 8: Journey Inside the Atom — Important Questions & Answers
Which subatomic particle has a positive charge?
- A. Electron
- B. Proton
- C. Neutron
- D. Nucleus
Answer: B. Proton
A proton carries one unit of positive charge. Electrons are negatively charged and neutrons have no charge.
A proton carries one unit of positive charge. Electrons are negatively charged and neutrons have no charge.
Who proposed the plum pudding model of the atom?
- A. J. J. Thomson
- B. Ernest Rutherford
- C. Niels Bohr
- D. John Dalton
Answer: A. J. J. Thomson
J. J. Thomson proposed the plum pudding model, in which electrons were embedded in a positively charged sphere.
J. J. Thomson proposed the plum pudding model, in which electrons were embedded in a positively charged sphere.
In Rutherford's alpha-particle scattering experiment, most alpha particles passed straight through the gold foil because:
- A. Atoms are mostly empty space
- B. Gold atoms are very soft
- C. Alpha particles have no mass
- D. Electrons repelled them strongly
Answer: A. Atoms are mostly empty space
Most alpha particles passed through undeflected because most of the atom is empty space. Only a few were deflected by the dense nucleus.
Most alpha particles passed through undeflected because most of the atom is empty space. Only a few were deflected by the dense nucleus.
A student says: "The atom is mostly empty space." Which model and experiment support this statement?
- A. Thomson model and cathode ray experiment
- B. Rutherford model and alpha-particle scattering experiment
- C. Bohr model and spectral lines experiment
- D. Dalton model and law of conservation of mass
Answer: B. Rutherford model and alpha-particle scattering experiment
Rutherford's experiment showed that most alpha particles passed through the foil without deflection. This supported the idea that the atom is mostly empty space.
Rutherford's experiment showed that most alpha particles passed through the foil without deflection. This supported the idea that the atom is mostly empty space.
An atom has 11 protons and 11 electrons. Which conclusion is correct?
- A. It is a positively charged ion
- B. It is a neutral atom
- C. It is a neutron
- D. It must have 11 neutrons
Answer: B. It is a neutral atom
Equal numbers of protons and electrons mean the atom has no net charge. Therefore, it is neutral.
Equal numbers of protons and electrons mean the atom has no net charge. Therefore, it is neutral.