Assertion and reason
Read exercise and reference answers
- Questions
- Reason
- It gave no account of why the revolving electron does not fall into the nucleus.
- Verdict
- Both are true; the reason explains the assertion.
- Assertion
- Rutherford's model could not explain atomic stability.
- Reason
- A definite orbit requires exact position and exact velocity at once.
- Verdict
- Both are true; the reason explains the assertion.
- Assertion
- Bohr's model contradicts the uncertainty principle.
- Reason
- Three quantum numbers describe each quantised energy state.
- Verdict
- The assertion is false and the reason is true.
- Assertion
- The quantum numbers must be assumed before solving.
- Reason
- Alpha-particle scattering showed the mass is concentrated, not spread.
- Verdict
- Both are true; the reason explains the assertion.
- Assertion
- Thomson's model was abandoned.
The reason must genuinely explain the assertion. Source: syllabus Chemistry Part I, Ch 2 Structure of Atom.