Atoms & Nuclei Flashcards for NEET — 20 cards

First 8 of 20 Atoms & Nuclei flashcards

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1. Card 1 of 20

   What was the main conclusion of the Rutherford Alpha-particle scattering experiment?

   Hint: Why did most alpha particles pass straight through?

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   Answer

2. Card 2 of 20

   What is the Impact Parameter ($b$)?

   Hint: If $b=0$, the scattering angle is 180 degrees (head-on collision).

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   Answer

   The perpendicular distance of the initial velocity vector of the alpha particle from the central axis of the nucleus.

3. Card 3 of 20

   State Bohr's Quantization Condition for angular momentum.

   Hint: Angular momentum is an integral multiple of $h/2\pi$.

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   Answer

   Where $n = 1, 2, 3...$ (principal quantum number).

4. Card 4 of 20

   How does the radius of the $n^{th}$ Bohr orbit ($r_n$) depend on the principal quantum number ($n$) and atomic number ($Z$)?

   Hint: For hydrogen ($Z=1, n=1$), $r_1 = 0.529 \text{ \AA}$ (Bohr radius).

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   Answer

   $r_n \propto \frac{n^2}{Z}$

5. Card 5 of 20

   Write the formula for the total energy of an electron in the $n^{th}$ orbit of a hydrogen-like atom.

   Hint: The negative sign indicates the electron is bound to the nucleus.

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   Answer

   $E_n = -13.6 \frac{Z^2}{n^2} \text{ eV}$

6. Card 6 of 20

   What is the relationship between Kinetic Energy ($K$), Potential Energy ($U$), and Total Energy ($E$) of an electron in an orbit?

   Hint: Total energy is negative. Kinetic is always positive. Potential is twice the total.

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   Answer

   $K = -E$ and $U = 2E$

7. Card 7 of 20

   Match the Hydrogen Spectrum series to their electromagnetic regions (Lyman, Balmer, Paschen).

   Hint: Transitions down to $n=1, n=2, n=3$ respectively.

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8. Card 8 of 20

   State the Rydberg formula for the wavelength of emitted light during an electron transition.

   Hint: $R$ is the Rydberg constant ($\approx 1.097 \times 10^7 \text{ m}^{-1}$).

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   Answer

   $\frac{1}{\lambda} = R Z^2 \left(\frac{1}{n_1^2} - \frac{1}{n_2^2}\right)$