COMEDK Atoms and Nuclei — practice questions
23 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice COMEDK Atoms and Nuclei in the app →Atomic number Z is:Mass number A is:Isotopes have:Bohr's first orbit radius for hydrogen:In hydrogen atom, energy of n-th orbit:Lyman series transitions land at n = ___, lying in:Rydberg formula for hydrogen lines:Half-life of radioactive sample is T₁/₂. Decay constant λ:Number of atoms remaining after 3 half-lives:Binding energy per nucleon for ⁵⁶Fe:Atomic mass unit u corresponds to energy:β⁻ decay: a neutron in nucleus converts to:Activity of N nuclei with decay constant λ:Half-life of ¹⁴C is 5730 years. Sample with 25% original activity is:Energy released in fusion: 4 protons → He-4 + 2 e⁺ + 2 ν_e (solar fusion). About:Wavelength of de Broglie wave of electron in n-th Bohr orbit:Nuclear radius R relates to mass number A as:For ¹H ground state to first excited state (n=2), photon required:Mass-energy equivalence: rest energy of electron (m_e = 9.11 × 10⁻³¹ kg):Activity of 1 gram of ²²⁶Ra (Avogadro = 6 × 10²³; T₁/₂ = 1600 yr):In a hydrogen atom transition from n=4 to n=2, the emitted photon belongs to:For He⁺ ion (Z = 2), energy of n=1 (ground state):Mean lifetime τ of radioactive nucleus vs half-life T₁/₂: