Physics · JEE

Important Questions: Composition and size of nucleus, atomic masses, mass-energy relation, mass defect for JEE

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Part of Atoms and Nuclei in JEE Main Physics.

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Q1PhysicsUnit 18: Atoms and Nuclei

Which of the following pairs are isotopes?

Q2PhysicsUnit 18: Atoms and Nuclei

Assertion The mass of a nucleus can be either less than or more than the sum of the masses of nucleons present in it. Reason The whole mass of the atom is concentrated in the nucleus.

Q3PhysicsUnit 18: Atoms and Nuclei

The missing particle in the reaction:

\underset{99}{253} \boldsymbol{E} \boldsymbol{s}+_{2}^{4} \boldsymbol{H} \boldsymbol{e} \rightarrow_{101}^{256} \boldsymbol{M} \boldsymbol{d}+

Q4PhysicsUnit 18: Atoms and Nuclei

A radioactive material decays by simultaneous emission of two particles with half-lives 1620 yr and 810 yr respectively. The time in years after which one-fourth of material remains, is

Q5PhysicsUnit 18: Atoms and Nuclei

Assertion A nucleus having enrgy

E_{1}

decays by

\beta

emission to daughter nucleus having energy

E_{2}

but the

\beta

-rays are emitted with a continuous energy spectrum having end point energy

\boldsymbol{E}_{\mathbf{1}}-\boldsymbol{E}_{\mathbf{2}}

Reason To conserve energy and moment in

\boldsymbol{\beta}

decays at least three particles must take part in the transformation.

Q6PhysicsUnit 18: Atoms and Nuclei

When a radioactive nucleus emits a

\beta

particular, the proton- neutron ratio

Q7PhysicsUnit 18: Atoms and Nuclei

\alpha

and

\beta

- particles emitted when uranium nucleus

_{92} U^{238}

decay to

82 P b^{214}

are

Q8PhysicsUnit 18: Atoms and Nuclei

Beta particles are essentially:

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