Which compound is aromatic? A. Cyclobutane B. Benzene C. Ethene D. Methane Explanation: Benzene follows Hückel’s rule.
Which reaction type forms larger molecule from smaller ones? A. Decomposition B. Addition C. Substitution D. Elimination Explanation: Addition combines molecules.
Which compound is strongest base? A. NH₃ B. OH⁻ C. CH₃COO⁻ D. Cl⁻ Explanation: Hydroxide is strong base in water.
Which element has highest ionization energy? A. Na B. Mg C. Ar D. K Explanation: Noble gases have full shells and high ionization energy.
Which process increases entropy most? A. Freezing water B. Mixing gases C. Crystallization D. Condensation Explanation: Mixing increases randomness.
Which interaction is responsible for beta decay? A. Strong B. Weak C. Electromagnetic D. Gravitational Explanation: Weak interaction governs beta decay.
Which phenomenon confirms existence of neutrinos? A. Photoelectric effect B. Beta decay energy spectrum C. Reflection D. Diffraction Explanation: Missing energy in beta decay led to neutrino hypothesis.
Which quantity is invariant in all reference frames? A. Velocity B. Time C. Rest mass D. Length Explanation: Rest mass is Lorentz invariant.
The Heisenberg uncertainty principle implies: A. Exact prediction possible B. Simultaneous measurement limits C. Deterministic motion D. No probability Explanation: Certain pairs cannot be measured precisely together.
Which radiation has shortest wavelength? A. Radio B. Microwave C. X-ray D. Gamma ray Explanation: Gamma rays have highest frequency and shortest wavelength.