CBSE 2022 · Region 3 · Set 3 · Q10 · 3 marks
(a)James Chadwick, in $\displaystyle 1932$, studied the emission of neutral radiations when Beryllium nuclei were bombarded with alpha particles. He concluded that emitted radiations were neutrons and not photons. Explain.(b)Two nuclei may have the same radius, even though they contain different number of protons and neutrons. Explain.
(a)
James Chadwick, in $\displaystyle 1932$, studied the emission of neutral radiations when Beryllium nuclei were bombarded with alpha particles. He concluded that emitted radiations were neutrons and not photons. Explain.
(b)
Two nuclei may have the same radius, even though they contain different number of protons and neutrons. Explain.
Marking-scheme solution
a) If the neutral radiation consisted of photons then from the conservation of energy and momentum, the energy of photons would have to be much higher than the energy available from the bombardment of beryllium nuclei with $\displaystyle \alpha$ - particles. He assumed that the neutral radiation consists of a new type of neutral particles called neutron
(b)
Radius $\displaystyle R$ of a nucleus depends on mass number $\displaystyle A, R A^{\frac{1}{3}}$
Where $\displaystyle A=N+Z$
In case of Isobars mass number is same but $\displaystyle N$ and $\displaystyle Z$ are not equal.
NucleiSize of the NucleusUnderstandshort_answermedium
More from Nuclei
- Explain the terms mass defect and binding energy. How are they related?2026 · asked 3×
- (i) Prove that the nuclear density is same for all nuclei. (ii) Draw a plot of potential energy of a pair of…2023 · asked 3×
- Differentiate between nuclear fission and nuclear fusion. Give one example for each with nuclear reaction.2026 · asked 3×
- Assertion: The binding energy per nucleon is practically constant for mass number in the range ( 30<A<170 ).…2025 · asked 3×
- (i) Write any two features of nuclear forces. (ii) If both the number of protons and the neutrons are…2026 · asked 3×
- Assertion: During formation of a nucleus, the mass defect produced is the source of the binding energy of the…2025 · asked 3×
- Which of the following statements is not true for nuclear forces?2023 · asked 3×
- Calculate the energy released in MeV in the following reaction: 1^2 H+ 1^3 H → 2^4 He+n Given: m( 1^2…2022 · asked 3×
CBSE Class 12 Physics past-paper question from the 2022board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.