Characteristic Spectrum

Q.

Which of the following configurations is associated with the biggest jump between 2nd and 3rd I.E.?

1. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^1$

2. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^2$

3. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^1$

4. $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^2$

Q. The energy level diagram of $K_{\alpha }$ x-ray emission is shown here. What is the correct inference?

1. The arrow in the diagram represents the jump of an electron from the K shell to the L shell.
2. The energy levels represent the energies of the atom when one electron is missing from respective shell.
3. The energy of the atom in K shell is lesser than its energy in L shell, but the diagram shows K shell at higher energy; hence the diagram is incorrect.
4. An x-ray carrying about 17 keV of energy will be radiated in the transition.

Q. The intensity of x-rays from Coolidge tube is plotted against wavelength $\lambda$ for a molybdenum target at an accelerating voltage of 35 kV. The minimum wavelength found is ${\lambda }_0$ and the wavelength of the $K_{\alpha }$ line is ${\lambda }_{K\alpha }$. As the accelerating voltage is increased from 35 kV to 70 kV -

1. $({\lambda }_{K\alpha }-{\lambda }_0)$ increases
2. $({\lambda }_{K\alpha }-{\lambda }_0)$ decreases
3. ${\lambda }_{K\alpha }$ increases.
4. ${\lambda }_{K\alpha }$ decreases.

Q. The wavelength of $K_{\alpha }$ and $L_{\alpha }$ X-Rays of a material are 20 pm and 140 pm respectively. Find the wavelength of $K_{\beta }$ X-Ray of the material.

1. 12.5 pm
2. 15.5 pm
3. 17.5 pm
4. 19.5 pm

Q.

Electrons with energy 80 keV are incident on the tungsten target of an X-ray tube. K-shell electrons of tungsten have 72.5 keV energy. X-rays emitted by the tube contain only: (IIT JEE 2000)

1. a continuous X-ray spectrum (|Bremsstrahlung) with minimum wavelength of $\approx$ 0.155 Å

2. a continuous X-ray spectrum (Bremsstrahlung) with all wavelengths

3. the characteristic X-ray spectrum of tungsten

4. a continuous X-ray spectrum (Bremsstrahlung) with minimum wavelength of $\approx$ 0.155 Å and the characteristic X-ray spectrum of tungsten.

Q. There is a vacancy in the L shell. Which of these transitions are possible?

1. $K\to L$
2. $M\to L$
3. $N\to L$
4. All of them.

Q. Any energy level marked here in the diagram can best be:

1. The energy of electron in that particular shell
2. The energy of atom when electron is removed from that particular shell
3. The energy of atom when electron is in that particular shell
4. It may be all of the above.

Q. Two ${}_{29}C{u}^{64}$ nuclei almost touch each other. The electronics repulsive energy of the system will be $(R_0=1\text{fm})$

1. $788\text{MeV}$
2. $7.88\text{MeV}$
3. $126.15\text{MeV}$
4. $0.788\text{MeV}$

Q. Two ${}_{29}C{u}^{64}$ nuclei almost touch each other. The electronics repulsive energy of the system will be $(R_0=1\text{fm})$

1. $126.15\text{MeV}$
2. $7.88\text{MeV}$
3. $788\text{MeV}$
4. $0.788\text{MeV}$